How to Choose the Right Substrate for Your Reptile

Substrate is the bedding that lines the bottom of a reptile's cage, and the substrate you choose can have a strong impact on the health of your pet. Here's how to choose the right substrate for your reptile.

When I was eight years old, I got my first reptile, and had never heard the word "substrate." But most reptile owners quickly learn that substrate is the bedding that lines the bottom of your reptile's cage and this seemingly unimportant cage decoration can strongly affect your reptile's health. The right substrate can providing hiding areas and proper heat and humidity, but the wrong substrate can lead to respiratory infections and even death. Different species of reptiles require much different varieties of substrate, but here are the general considerations you should examine before buying a substrate for your turtle, tortoise, snake, or lizard:

What is the Animal's Natural Environment?

Reptiles live in a variety of habitats and biomes, and the first thing to take into consideration when buying a substrate is how your reptile lives in the wild. Water dwelling amphibians will be almost universally happy with large, non-dusty river rocks that are too large to swallow, but other reptiles require more thought. Research your pet's natural habitat and buy a substrate that can help to mimic the natural terrain your reptile might be walking or crawling on in the wild. Desert dwelling reptiles will enjoy sand, while forest reptiles may do better with moss or potting soil. Animals that require very high humidity may thrive in a cage lined with moist paper towels that are changed daily. Envision what your pet's natural environment would look like and use this as your starting point for choosing a substrate.

What Climate Does Your Reptile Like?

Substrate can strongly affect the climate in your reptile's cage. Moss tends to hold moisture well, which works great for animals that require high humidity, but this same high humidity can be dangerous and even fatal for desert dwellers. Similarly, sand holds heat well, which may be the most important consideration for desert dwelling reptiles, but animals that live in more temperate climates may overheat in sand.

What Are Your Pet's Roaming Habits?

Some reptiles are strictly terrestrial, which means they never climb in trees. Other like to burrow. Research your animal's behavioral habits in the wild and try to find a substrate that helps mimic them. Arboreal ("in the trees") animals will do well with a simple substrate but lots of branches and hammocks to climb on. Animals that like to dig and burrow will need a thicker layer of substrate that allows them to create holes and "remodel" their habitat as they see fit. Desert dwelling reptiles often enjoy thick sand formed into mounds. This can be problematic for tortoises, who tend to be awkward walkers, but most lizards and snakes will appreciate substrate that is thick enough to form into mounds.

Does Your Reptile Have Sensitive Skin?

Snakes have to slither across their substrate, which means constant rubbing on their skin. Consequently it's important to avoid any substrate with rough edges that could cut them. Other reptiles may be sensitive to dusty substrate or may have trouble breathing in very thick substrate. Research any health problems your reptile is prone to and avoid any substrate that could exacerbate these.

What Happens If Your Pet Eats Substrate?

Most reptiles will periodically try to eat their substrate, so it's vital that you choose a substrate that is non-toxic. Many substrates sold in pet stores, surprisingly, are actually highly toxic, so it's important to research what is in a substrate before you buy it. Potting soil filled with fertilizer and play sand that has been bleached should also be avoided. In addition to toxicity, there is also a risk of impaction with substrate, which is what happens when an animal eats something but its body cannot process or digest it. The object essentially becomes lodged in the animal's stomach and can lead to a slow and painful death. Given the risk of impaction, a good strategy is to use a substrate that is either too large for your reptile to swallow an individual piece or that is both fine enough and non-toxic to be easily digested. Several pet companies make substrates that are designed to be eaten and can provide your pet with valuable nutrition. Consider calci-sand for lizards or alfalfa hay for some tortoises.

If you're in doubt about what substrate to use for your reptile, a good bet is to use no substrate or paper towels until you can get advice from a qualified vet about the best choice for your pet.