NEHERP - Vivarium Construction 102 - The most complete vivarium building articles online!

Vivarium Construction 102

The 2'nd Part Of The Most Complete Vivarium Building Guide On The Web!

This article pertains to vivariums built using techniques & supplies described in Vivarium Construction 101 [!]

If your vivarium wasn't built to the specs outlined in Vivarium Construction 101, much of this article's advice will not apply to your enclosure!

Introduction

So now that you've read & understand the basics of vivarium building as covered in our Vivarium Construction 101 article, let's dig-in and see what else there is to learn about the full aspect of vivarium building. Much like VC101, this article will touch on a handful of topics including the basics of what to expect in a freshly planted vivarium, how to identify & work with different types of microfauna, and other slightly more advanced topics. This will be the 4'th addition to our vivarium construction & care series, and we hope it'll help readers on their quest to fully grasp the concepts of long-term vivarium building as a hobby.

Freshly Planted Vivariums

The first two months after a vivarium is planted are usually regarded as the most important, since so much is going on inside the enclosure. During this time, the plants will acclimate to their new surroundings, the microfauna will have it's initial population boom, and the vivarium may go through it's 1'st natural mold/fungus cycle. During this time, you may see sprouts of mushrooms and/or mold, Microfauna populations rise, and even a small amount of plant die-back. Left alone, this process will usually settle itself and turn around for the better within a couple weeks. This is generally referred to in the hobby as a vivarium "cycling". This mold/fungus cycle will greatly assist the beneficial microfauna establish a large enough population for long-term success. Most vivarium builders suggest allowing the enclosure to cycle for at least one month before introducing animals, since doing so minimizes exposure to the initial cycling of the enclosure, and also gives plants & microfauna much-needed time to acclimate before being disturbed by the inhabitants. (Waiting 2 months is even better!)

Plant Acclimation

The first 3-6 weeks inside a vivarium are by far the most critical for the long-term success of plants within the enclosure. During this time, some plants may die-back before sprouting new growth & throwing new roots. Between the shipping transit time (if you'll be buying plants online), processing procedure, and initial planting/mounting, the plants will appreciate a little time to settle in before introducing inhabitants that would disturb them. It's best to pay extra close attention to new plants during the acclimation period to ensure they are adjusting well to life in their new home. The type of care will vary from species to species, so you want to make sure that each plant's watering & lighting schedules are followed carefully until they've thrown roots & adjusted to life in the new habitat. Once acclimated, plants will be more apt to survive if you occasionally forget to mist, and they will also better tolerate abuse from inhabitants. Epiphytes are plants that grow on another plant or object, and derive moisture/nutrients from the air, rain, or mist around them. For epiphytes, you want to ensure that the surface the plant is mounted on remains moist during the acclimation period. Most vining/trailing epiphytes won't grip & grow against something that is completely dry, so keep that in mind as the vivarium is planted. Ideally, a misting system can be used to ensure misting schedules are kept consistent, and also to make sure plants will remain hydrated while you are away. While not necessary for long term success, it's a big help that can make a natural environment even easier to care for.

Microfauna Acclimation

During this time, the beneficial microfauna species you introduced will establish themselves with the enclosure as well. It's important to leave them undisturbed during this time by not introducing inhabitants until the 3-6 week mark. Some enthusiasts add very small amounts of Repashy Bug Burger or Morning Wood to freshly planted vivariums, to help isopods & springtails more quickly establish themselves. After 3-4 weeks of acclimation, at least some of the microfauna population should be visible under & inside the layer of leaf litter provided. A healthy microfauna population is a good indicator that a vivarium is ready for inhabitants.

Fungus & Mold

Having a little fungus among us isn't always a bad thing!

The following information is provided as a non-scientific reference as to what's commonly experienced by vivarium enthusiasts; and is not to be used as a reference guide for safety. We're vivarium geeks; not Mycologists!

Most experienced vivarium builders have seen mushrooms (and occasionally a little mold) before, but it's not so commonly discussed in vivarium building articles; probably for fear of scaring away new & inexperienced enthusiasts. Before we continue on this under-discussed topic, it's important to understand this section pertains to properly setup vivariums with appropriate substrate. If a vivarium isn't properly built, the enclosure has a far greater chance of encountering a dangerous anaerobic soil condition.

While mold & fungus in daily human life are often considered bad things, both play a crucial and necessary role in nature's life cycle. During a vivarium's first few months, it's common to occasionally notice a little natural mold here & there as the vivarium establishes itself. Although at least some natural presence is virtually guaranteed (and necessary, as in nature), it will be more apparent in highly humid vivariums for their ideal growth conditions. Please keep that in mind moving forward, as vivariums with relative humidity levels below 80% may have little to no visible growth, as conditions are not as conducive. While most hobbyists regard the commonly seen types of mold & fungus as harmless, limiting the inhabitant's unnecessary contact with them by not introducing the animal to the vivarium until 4-6+ weeks after the vivarium has been set up is always good practice. The wait period also allows plants and microfauna to establish themselves, as explained earlier in this article.

Fungus & Mushrooms

Springtails say a mushroom is a fungi to have dinner with!
The vast majority of a vivarium-dwelling fungus's life cycle is spent underground, with mushrooms presenting themselves (in some species) as it's "fruiting body" or reproductive stage. Mushrooms are occasionally present earlier in a vivarium's life, but are usually a little more commonly found as the vivarium ages and the fungus matures. Fungus will most often occur in highly humid environments, and most commonly presents itself on wood or other organic decor. Both fungus and mold play a crucial part in nature's ability to break down, process, and essentially recycle organic waste. In fact, over 90% of all plant species benefit from mycorrhizal relationships. (Mycorrhiza = A symbiotic relationship between the roots of a vascular plant & a fungus.) Naturally forming fungus acts as a food source both above & beneath the substrate layer for Springtails & other beneficial vivarium dwelling detritivores. Pictures of in-vivarium mushrooms are often shared on forums by enthusiasts, as some of the growth patterns can be very interesting. Some hobbyists invest in mushroom spore kits to inoculate wood & other decor items, giving their vivarium a "grown in" look when the mushrooms sprout. Some of these spore kits include bioluminescent species that can look spectacular!

Common Mold

The white "webby" or fuzzy stuff
The most common mold seen in vivariums is white & fuzzy, and is most often prevalent in freshly planted vivaria. (Shown right) We get an email or two about this every once in awhile, but most hobbyists & vivarium builders say, "It's not usually something to be concerned about.". Some hobbyists recommend misting it with water to (usually) make it visually disappear, or you can choose to leave it alone, which will allow you to view the Springtails as they surround & devour it. Try to keep in mind just how natural what you've built is! If left alone, most "new vivarium" mold issues disappear within a couple weeks, as the microfauna devours it while they do their job of keeping the vivarium healthy & properly cycling. In turn, the Springtail population will be able to grow quicker, due to the extra food (i.e. mold) present when the vivarium is initially planted. This initial mold cycle acting as a natural food source for beneficial microfauna is one of the reasons builders let vivariums cycle for at least a month before adding inhabitants.

Excessive Mold

This can be a sign of an underlying issue ranging from something simple, to something serious.
If you are seeing excessive mold growth, chances are there may be something inside the vivarium that isn't well suited to the humid environment, and is beginning to break down. This is especially true with grape wood, and many other types of less appropriate vivarium wood (explained in detail on our Vivariums 101 Article). If a certain hard-decor item is causing persistent & unsightly mold, it's careful removal may be necessary. If your substrate has grown mold on it, that can be a serious concern, since appropriate vivarium substrates rarely support this. Using inappropriate vivarium substrate greatly increases the risk of an anaerobic condition, and can cause this & other serious problems. Appropriate vivarium substrates for tropical & temperate vivariums include ABG Mix, NEHERP Vivarium Substrate, similar (tree fern, fir bark, fine charcoal, sphagnum, coir/peat) blends, and other home-made "clay style" substrates. If you are seeing excessive amounts of mold, consider asking someone with experience for help on a vivarium-experienced forum such as Dendroboard.com. (ext. link) Excessive mold growth is cause for concern, so when in doubt, place the inhabitants in a temporary home until the cause has been found.

Microfauna

Springtails

The good, the bad, and the ugly

Everyone who's read into vivariums knows that microfauna (Springtails and Isopods) are a natural, necessary, and extremely beneficial part of the vivarium building process. What about the bugs that nobody talks about? Some beneficial bugs are nearly always present in a vivarium, but aren't often mentioned... We figure a list of commonly seen vivarium microfauna is in order to help people be better prepared for what really happens when you build a live vivarium.

Springtails

Isopods

The Good Bugs

Beneficial Critters that clean up the organic waste inside a vivarium
Springtails and Isopods are the most common types of beneficial vivarium microfauna, and cultures of each are usually introduced to a vivarium upon it's completion. This ensures the bugs will be able to establish a sustainable population within the substrate & leaf litter. Although Springtails & Isopods are the most commonly added beneficial microfauna types, they certainly aren't the only members of the "good bug club".

Detritivore mites and free living soil nematodes (which are considered decomposers, for this purpose) are in fact already living inside the vast majority of live vivaria; regardless of whether or not the owner intended for them to be there. Both are so tiny that unless you've got excellent vision, you'll likely need a magnifying glass to see them. Detritivore mites are tiny, round, (usually) brown or tan slow-moving insects. Soil dwelling nematodes appear as thread-thin (usually) semi-translucent worms. Both types live nearly everywhere on earth, so avoiding them completely isn't something that's generally feasible. Both detritivore mites & soil-dwelling nematodes generally pose no threat to your inhabitants and are technically beneficial to your vivarium unless the population grows to large numbers. (Enough to stress the inhabitants.) In general, springtails are an excellent method to control detritivore mite overpopulation issues. Adding springtails when the vivarium is 1'st built will help ensure that they will out-compete the detritivore mites, and keep their population down to a perfectly acceptable level long-term. Also, limiting the amount of excess supplements that hit the vivarium floor during feeding is another way to limit the population, as both of these harmless detritivores will enjoy chowing down on the extra food source. It's worth mentioning that a vivarium does not raise the risk of encountering predatory/parasitic mites.

Fungus Gnat

The Neutral Bugs

Bugs that are fairly common, natural, and usually (but not always) go away on their own
Fungus Gnats are a small (about 1/8") fairly common and harmless flying insect most commonly seen in more freshly planted vivariums. The larvae are generally beneficial, as they eat decomposing material & fungi, which aids in the decomposition of organic wastes in the vivarium. While healthy plants are generally not negatively affected by these, extremely sensitive new-growth plant roots & seedlings can be damaged by the larvae. Despite that fact, we consider these to be overall neutral, although the Gnats themselves can be irritating. Springtails can/will out-compete the larvae in a well built vivarium, so adding springtails when the enclosure is 1'st built is usually your best bet for control. Allowing the vivarium to acclimate for 3-4+ weeks before introducing herp inhabitants will also help minimize the risks, as the well-established microfauna populations will be more likely to keep up with the added detritus. Common smaller populations of fungus gnats usually die-off with no human effort as Springtails & other beneficial microfauna out-compete them, however occasionally these can establish themselves in the right conditions, and may require a little extra attention. If fungus gnats are introduced to an enclosure before a healthy beneficial microfauna population is established, or with an abundance of detritus, it's much more likely for these to become a pest. In that case, the life cycle can be ended by removing the inhabitant species, and adding Sticky Stakes (or similar non-chemical flying insect trap) for a few weeks to catch the adult Fungus Gnats. The entire life cycle of a fungus gnat is only about 4 weeks, so the problem will resolve itself fairly quickly, upon which time it's safe to remove the Sticky Stakes & re-house the herp in the gnat-free environment. To be clear, these natural decomposers go away naturally (or don't appear at all) the vast majority of the time.

The Bad Bugs

Plant parasites that are very easy to avoid with the proper precautions
These are the bugs to avoid, as they are detrimental to a vivarium's growth, and some can quickly ruin a beautiful setup. Some of the more common vivarium pests include millipedes, scale insects, slugs, snails, nemerteans, and mealybugs. (Use google images if you are trying to ID a pest, as we didn't have access to any of them for pictures!) While none of these pose a threat to your inhabitant's health directly, larger populations can cause them undue amounts of stress, which can lead to health issues. All the aforementioned species have their own way of being detrimental to the enclosed flora, and can quickly ruin a setup if left unchecked.

Prevention is key... Following the easy, standard preventative measures will virtually eliminate the chance of encountering any of the above pests. A simple defense against these unwanted inhabitants is through plant processing, which is a necessary and critical part of professional-grade vivarium building; regardless of where your plants came from. (Learn more about why on our plant processing guide.) Each of these pests can virtually always be avoided through proper plant processing during the vivarium's construction. Another vector for introducing these unwanted pests is by utilizing decor items found outside for use in your vivarium without proper sterilization. We strongly recommend against using "found" items that aren't able to be sterilized this reason. All non-sensitive hard-decor items that can fit into a pot should be boiled as a precaution. This includes things like wood decor, leaf litter, hides, and more. Seeding your vivarium with "wild caught" microfauna from outside your home is an unnecessary and risky practice, as you can also introduce many plant parasites (or worse) into your vivarium along with the bugs you intended to introduce. Processing plants before planting them, using captive bred microfauna, and sterilizing all decor items will give your vivarium the best chance for long-term success.

The "Ugly" Bugs

Very uncommon, and a little different than the easy-to-prevent bugs on the "bad" list.
This is an uncommon household pest that can find it's way into a vivarium; not the other way around. Phorid flies won't arrive with vivarium supplies or any herp-related items, but instead most commonly show up with older kitchen produce, around kitchen garbage, and even from sink drains in your home. We mention these flies mostly for people who work with produce-eating reptiles or insects, as the presence of exposed produce increases the likelihood of encountering Phorid flies in a home. We know of only a couple hobbyists who have ever encountered Phorid flies, but if we're able to help just one hobbyist prevent these in the future, it will have been worth mentioning on this article. These humpbacked flies are about the size of a common fruit fly (D. melanogaster), but their habit of quickly running before they fly (when disturbed) sets them apart & makes them easy to differentiate. If Phorid flies are already present in your living space, they can technically breed inside a vivarium if they are able to find a way inside, so be sure to eliminate all sources of Phorid flies in your home before proceeding with a vivarium build. They aren't directly harmful to inhabitants, but they can be a nuisance. To be clear, these flies are an extremely uncommon risk to simply be aware of moving forward.

We've built a substantial amount of vivariums at NEHERP over the years for customers, employees, and for use in our breeding rooms. None of our vivariums have ever encountered any pests from the "bad" list, due to us following the simple guidelines above. It really is that easy to do it right and have complete peace of mind. There's an old saying that fits this scenario perfectly: "Do it right, or do it twice!

Removal Of Pests In-Vivarium

If the preventative measures were skipped during vivarium setup, there's still hope!

If you've already built your vivarium and skipped the industry-standard plant & decor processing procedures, with any luck you might still be OK. However on the off chance that one of the above pests found it's way into your vivarium, there is a fairly simple & inexpensive procedure you can use to rid the enclosure of them. It's called Co2 bombing, and has been popularized by many users of online forums. We need to stress that this procedure can easily be avoided if the proper preventative measures are taken. Co2 bombing is a "last ditch effort" to save a vivarium, and is not considered a standard practice. First, the inhabitants must be removed from the enclosure. Then you'll need to seal the bottom and sides by covering up any gaps, vents, or door jambs with tape (if applicable). After the bottom & sides are well-sealed, simply place some dry ice in a basin of water above the terrarium and allow the Co2 gas it produces (as it evaporates) to flow into, and fill up the vivarium. Be sure that the heavier Co2 gas completely displaces the air in the enclosure. Once it's full of Co2, close/seal the top to keep any drafts in the room from blowing air into the terrarium if possible. Leave the vivarium completely full of Co2 overnight, and repeat the cycle again 2-3 weeks later to remove any pests that were in-egg during the 1'st treatment. Dry ice can usually be purchased from your local ice shop, and should be handled extremely cautiously to avoid burns. Co2 bombing will kill your springtail/isopod population, so restocking your vivarium with them after the last treatment is really the most expensive part of this procedure. The good news is, your vivarium's plants will receive a huge boost from this process, as they thrive on Co2!

Cross Contamination

Cross contamination is when pests or pathogens are transferred from one enclosure or animal to the next. This is NOT a vivarium-specific topic, and should be followed with any of your enclosures. There are countless methods to help prevent cross contamination, and any responsible vivarium builder (or exotic animal keeper) should take measures to help minimize the risks. The best practice is to simply limit contact between any item exposed to multiple enclosures without 1'st sterilizing it. This includes your hands, misting bottles, decor, and more. Following anti-cross contamination procedures helps to prevent the possibility of spreading an ailment or plant pest from one enclosure or animal to another. Regardless of how healthy your vivarium and/or inhabitants are; the safest way to think is, "Each vivarium and each inhabitant should be completely separated from any contact with the next". We've put together a quick list of commonly used ways to prevent cross-contamination between live vivaria & your animals. These are all easy methods than anyone can adhere to with very little (if any) cost.

Cross Contamination Checklist

A few of the most common & easiest to prevent common instances where cross contamination can occur

Sanitize your hands between handling individual animals, vivarium interiors, plants, and any other surface that comes into contact with your animal(s).

Never transfer a decor item from one inhabited vivarium to another without completely sterilizing it 1'st.

Wash your mister often! How many times have you touched an animal, it's food, or any surface inside a vivarium before giving it a quick spray down?

Bug-proof your vivariums (if offering feeder insects). Insects can carry pathogens from one vivarium to another if they are able to travel freely between them.

Bulkhead drainage tubing should not be directly connected between vivariums. (This is explained in more detail a few paragraphs down)

Resist the urge to allow guests to hold one animal after another. (At a bare minimum, have hand sanitizer ready for use between handling different animals)

Child-proof and/or lock your vivariums if you have young'uns in your home.

Want to transfer plants grown in one vivarium in another? Simply process the plants before introduction to minimize the associated risks.

Pruning plants? Make sure your pruning scissors or razor is sterilized between each vivarium.

Escaped fruit flies? Fill a cup with apple cider vinegar & dish soap & place it near the vivarium to create a great-working fly trap! (Prevents flies from traveling)

Sanitize your hands before preparing & handling food for your collection.

Siphoning waste water? Don't forget to sterilize the tool you use between vivariums.

Drainage Layer - Advanced

A key part of a live vivarium!

It's a whole lot more than just "where the excess water drains to". The drainage layer is home to a population of beneficial bacteria and microfauna, which are both critical to your vivarium's health. Enclosures should always have a shallow water table in the drainage layer to keep humidity at appropriate levels for both the plants & inhabitants. (We recommend a water table depth of 1/2"-3/4" for most enclosures) For many enclosures that are hand-misted, the drainage layer water will not need to be changed or flushed in the vivarium's life. However, the frequent misting required by some species can add too much water to the drainage layer, which can require draining. This is especially true if you'll be using a misting system on your setup, as they can add a considerable amount of water to an enclosure over the course of a few misting sessions. Water from the drainage layer should never rise high enough to come into direct contact with the substrate layer, and ideally should be kept at least 1/2" away from the bottom of the substrate layer. This helps to prevent substrate saturation, which can lead to an anaerobic soil condition.

So what happens when too much water ends up in the drainage layer? Before the water level is high enough to touch the substrate layer, it's important to remove the excess amount. If you hand-mist, this is something that isn't usually necessary more than once every couple months (if ever). Waste water removal can be done a number of ways depending on your particular application, with the two most popular options explained below.

Manual Siphoning To Remove Waste Water

Example of vivarium waste water drainage removal

If you left yourself a drainage point (covered in Vivarium Construction 101), you can lead any form of tubing down into the drainage layer & siphon water directly for quick & easy waste water removal. If your setup does not have a waste water access point, you can use a turkey baster style waste remover, or siphon line to drain the excess water. To remove water from the drainage layer using this method, you'll need to dig out a very small area of substrate along the edge of the vivarium to access the drainage layer below. Once the substrate is dug out to the depth of the screen separator, slide the tool or line down into the drainage layer while being careful not to allow any substrate to fall past the screen separator. Once the appropriate amount of water is removed, fill in the substrate where it was dug out to finish the job.

Bulkhead Overflow To Remove Waste Water

If you utilize an automated misting system, or mist very heavily, you might be better off installing a bulkhead kit on your enclosure to allow it to freely drain into an external basin once the water table exceeds a certain height. With a bulkhead connected to drainage tubing, you have virtually no chance of the water level exceeding what's appropriate, so it's also great for added peace of mind. Bulkheads must be installed on an empty enclosure, and require drilling glass for installation, so be sure to do this slowly & carefully. We recently starting carrying a high quality diamond tipped glass drill bit specifically for our bulkhead kit. A good drill bit will drill faster, cleaner, and have less of a chance of breaking the glass than a low quality bit will. Hobbyists with only one or two vivariums may find it easier to use a bulkhead as a manual drain point by angling the bulkhead's output tube upward when not in use. This skips the need for running tubing to a drain, but does require the owner to keep an eye on the drainage layer to ensure it's drained when necessary. Both of the above methods are acceptable, although running tubing to a basin is more of a hands off & professional setup.

Waste Water Removal - An Eye On Cross Contamination

An example of something that separates good husbandry from great husbandry when using bulkheads for drainage

An example of something that separates good husbandry from great husbandry when using bulkheads for drainage

Drainage tubing from one vivarium should not be directly connected from one enclosure to another to eliminate the risk of cross contamination of any possible pathogens. If you have less than a few vivariums, it's often easiest to allow each enclosure to drain to it's own waste water reservoir (see 1'st diagram). If you have a few vivariums, each enclosure's drainage line should drain separately from the next, and they should not come into contact with each other (as illustrated in the 2'nd diagram above). Air gapping drainage as shown can be a little tricky, but once it's set up, it's an excellent peace of mind for you and your vivarium's inhabitants. An air gap drain is when water falls out of a tube or pipe, into a larger waste water reservoir or collection pipe without the two being directly connected. (Thus "air gap") This seemingly trivial gap between the drainage tube & collection pipe (or waste water reservoir, depending on your setup) greatly reduces the risk of direct cross contamination between vivaria by working like a biological one-way valve. A single shared drain tube (3'rd diagram) is less than ideal, due to the increased possible risk of cross-contamination between enclosures.

Waste Water Sterilization

Another example of something that separates good husbandry from great husbandry

The most responsible breeders sterilize their wastewater before discarding it. This practice takes another step towards ensuring that your hobby has absolutely no impact on the environment around you. After removing the reservoir from the vicinity of your inhabitants, add bleach (roughly 10% for sterilization, which is 1 1/4 cups per gallon of water) to the reservoir for a few minutes before expelling it. If you have access to germicidal bleach, use it! Considering how quick & easy this step is, it should be considered standard practice for responsible vivarium enthusiasts. Be sure to rinse-out the freshly sterilized container with water before bringing it back near your vivariums.

False Bottom vs Standard Drainage Layer

This is an often-debated topic for vivarium builders. False bottoms are an alternative to using a standard drainage layer (with leca, hydroballs, or LDL substrate) which elevates the substrate layer above the water level on a platform which was cut to fit the enclosure. This platform is most commonly made from "egg crate" light diffuser material wrapped with screen, and elevated by PVC fittings. (It could alternatively be propped up using anything that's pH neutral, waterproof, and vivarium safe) Some advantages to using a false bottom style drainage layer include less weight, lower cost, and it arguably makes introducing a water feature easier. Advantages of standard drainage layers include far more surface area for microfauna & beneficial bacteria, the ability to support heavy decor items, and lastly it offers an easy way for microfauna to crawl back up into the soil after going down (or falling down) into the drainage layer. While neither way is "wrong", we believe standard drainage layers are usually the best bet.

Red Flags

Here's a list of some common red flag issues that require immediate attention. If you see one of these red flag items in your enclosure, you should address the issue as soon as possible to ensure long-term success in your vivarium & the health of your inhabitants.

Persistent mold directly on substrate
If your substrate is persistently moldy, it may be due to the use of an improper substrate. Improper substrates for vivarium use include coconut fiber, peat, sphagnum, compost, potting soil, or any mix of these types. All these substrates have a far, far higher risk of compacting in a vivarium than specially blended vivarium substrate, which can lead to a dangerous anaerobic soil condition. If your soil goes anaerobic, it will need to be removed & replaced with an appropriate vivarium substrate. An anaerobic soil condition is considered unsafe for contact with your inhabitants, so they should be removed ASAP. Proper vivarium substrates have all the necessary components to fight compaction long term, support microfauna growth, and stay "airy" enough to support healthy plant life.

Any foul "pond-like" smell
Once acclimated, a vivarium should smell like a clean forest, with no unpleasant odors. If you notice a foul odor in your enclosure, chances are either the substrate is anaerobic, or the water in the drainage layer needs to be replaced. Both issues are cause for concern, and can be fixed using information found on this article.

Chewed leaves
Often a sign of a bug on the "bad list" (above), chewed leaves can be an early sign of an unwanted inhabitant living in your vivarium.