So what do we mean – exactly – when we use the word substrate? According to the dictionary, it’s another word for substratum, meaning what lies beneath.
The substrate, then, is what we put on the floor of our animal’s habitat under the decor. It’s what our animal walks on, where it makes its home, and what it interacts with every time it moves around the space it lives in. It can be loose, tiled, carpeted or bioactive according to species and/or inclination of the owner – but what is the difference, and why should we choose one over another?
The choice is utterly bewildering, and the horror stories bandied about online as to the consequences of choosing badly can be horrific, at best. So let’s go back to first principles.
Why do we need substrate?
Well, we need a floor! This floor covering can serve several purposes: it can affect humidity levels, provide environmental enrichment for the enclosure’s inhabitant, and can add to the aesthetics of the enclosure.
But isn’t it dangerous?
Let’s get this one out of the way right at the beginning! Yes, if an animal eats substrate (a behaviour called pica), it can cause it a problem. And it’s certainly true that if you remove the substrate completely, you remove the possibility of that happening. But in the wild animals run around on, hide in and feed on the dirty ground, and are ingesting foreign material all the time; the difference is in the environmental conditions. They are exposed to the appropriate levels of UV, temperature, and humidity for their species. Everything they are exposed to they have spent tens of thousands of years evolving with, and their systems exist in harmony with their surroundings.
So when an animal exhibits abnormal behaviour (in this instance, pica), we need to look at the entire habitat. Taking this holistic approach will prevent problems occurring in the first place, and will quickly correct any that do occur.
In short, don’t blame the substrate – it’s a symptom, not the disease.
There are so many! How do I choose?
We are often asked which substrate is best. Well, that’s a difficult question!
If we take the holistic approach mentioned above, it makes selection a little easier. Where does your pet live in the wild? Is it a forest species, does it live in dry grassland, rocky deserts, up a tree, down a burrow? Looking at where they evolved to thrive will tell you an enormous amount about what they need to be happy in captivity.
Once we’ve narrowed it down to dry or humid, we need to consider what type of substrate to use. Do we go with a small grain, like a fine sand, or a soil based one, or wood chips? It’s a balancing act between what would be found in the wild and what works for us.
It’s easier for some species than others, of course; bearded dragons, leopard geckos and corn snakes have been kept and bred in captivity for so long that they are extremely adaptable when it comes to the surface they walk on. This doesn’t mean that you shouldn’t choose carefully, simply that you have a wider range to choose from!
So what are my options?
Let’s start with dry conditions. These substrates work for our arid habitat pets – bearded dragons, leopard geckos, corn, rat and king snakes, and desert specialists such as uromastyx.