Reptile substrate, or bedding, is what goes on the bottom of your reptile’s cage and provides grip, absorbs waste, help with keeping the tank dry or humid. In this post, you will find the most common, and best and worst substrates for reptiles and exotic pets, and pros and cons of each substrate type.
Substrates in this post are in no particular order, and list the most common substrate options. Some substrates might be more suitable for your particular pet, so make sure to consider their pros and cons before choosing.
Type 1: Topsoil, and topsoil mix
Topsoil mix is one of the best substrate options for many reptiles and other exotic pets. Topsoil should be pesticide-free and additive-free. You can make your own mix or find a ready topsoil mix for reptiles like this one
Depending on what humidity your pet needs, you can mix topsoil with some of different substrate. For example, for pets that like burrowing and come from hot places – topsoil can be mixed with playsand (60/40 or similar proportion).
And for pets that need higher humidity levels – you can use topsoil on its own, mix topsoil with some playsand, coconut coir and/or cypress mulch. This will help retain more humidity. As with another loose substrate, it might be ingested, but there is no risk-free loose substrate.
Type 2: Reptile carpet
Reptile carpet like this is another substrate/bedding that is popular for reptiles and some exotic pets. However, you should only use reptile carpet for pets that come from hot/arid places. That’s because for humidity loving pets, carpet will harbor bacteria and start smelling.
Always have a spare piece of reptile carpet, because you will often need to take it out and wash it. Wash with soap and hang to dry. Because carpet is not loose, this excludes possibility of ingestion. It also looks nice in a cage.
Type 3: Bark chips or shredded bark
Bark chips is a substrate that is often used for pets that need higher humidity levels. This bedding can help with shedding and allow burrowing. Bark chips are also decorative and look nice in a tank.
However, there is an impaction risk. If you decide to use bark chips, make sure to choose chips that are large, so that your pet doesn’t want to eat them.
Bark chips don’t hold heat very well, but are fine for humidity loving animals. You can use bark chips in a mix of topsoil, cypress mulch etc. Replace once a month. Orchid bark or fir bark are popular options.
Type 4: Coconut coir/fiber/Eco Earth
Coconut coir is a good substrate for humidity loving pets, and doesn’t suit heat requiring ones. That’s because coconut fiber is dusty when dry and can cause eye irritation in your pet. Coco coir allows digging and is also good for burrowing animals.
If your pet needs high humidity levels, you can use coco coir mixed with some topsoil and/or mulch. That will prevent it from getting too wet and sticking to your pet. However, you can use it on its own. Replace fully once a month or so.
Type 5: Cypress mulch
Cypress mulch is also a good substrate for humidity loving pets. It helps retain moisture in the tank, regulating humidity levels. Cypress mulch like this can be used on its own or in a mix, and looks aesthetically pleasing.
Because it’s loose, it does pose a risk of impaction, however should be passed in smaller quantities. To avoid impaction, put food in a bowl and even a mat under a bowl.
You can mix cypress mulch with other humidity retaining substrates to make a tropical mix (topsoil, coco coir and some playsand, for example. or just 50/50 topsoil and mulch).
Type 6: Aspen
Aspen is not the best substrate, but is often used for pet snakes. It can get dusty easily and start molding quickly in high humidity environment. However, it is great for burrowing and easy to clean, so would suit pets that require medium humidity levels.
If you decide to use aspen, make sure to spot clean and don’t allow it to get too wet. When adding aspen to the tank for the first time, allow time for your pet to compress it before you feed it. This will help avoid ingestion.
Type 7: Paper towels, butcher paper or newspaper
Paper towels, butcher paper or unprinted newspaper is one of the best substrates for your exotic pet when you just bring it home, or for pets in quarantine. It is also a great substrate for hatchling and babies. That’s because it’s easy to change, can pass if ingested and allows you to monitor their poop.
It might be a good substrate for adults, but would not be very suitable if your pet requires high humidity. That’s because it can create mess and rip easily. It’s also not aesthetically pleasing.
Type 8: Slate or ceramic tiles
Tiles is another great type of substrate/bedding for heat loving pets. That’s because it can’t be ingested, is easy to clean and loos great in a cage. What is more, it retains heat very well – it also emits heat after the lights are off. This can help mimic natural living conditions where heat is emitted from rocks after dawn.
If you decide to use tiles, make sure they are not glazed. You can ask to cut tiles to your required size, and even split the tank and use another type of bedding on another side. Slate and ceramic tiles are the best types of tiles that you can choose from.
Type 9: Alfalfa pellets
Alfalfa pellets have been used as a substrate for exotic pets for a long time, but it is getting less popular. While alfalfa pellets like this are rather absorbent, allow digging and can be digested, they have a distinct smell.
It can also mold rather quickly if it gets too wet. If too dry, it can get dusty and cause respiratory problems, but if too wet, will mold and clump. It might be used, but only for pets with medium humidity requirements (40-50%).
Type 10: Sphagnum moss (mixed with another substrate type)
Sphagnum moss is great for increasing and maintaining humidity for high humidity requiring reptiles. However, you would not use it on its own (you can use some in a shedding cave when your reptile is shedding for example).
But in general, you can mix in some sphagnum moss with another substrate such as coco coir or mulch, on one part of the cage. You would need to keep it moist, but not soaking wet.
Type 11: Sand
Sand has been used as a substrate for many years, for different pets, but is a big source of debate. Many reptile owners state that they have been using sand for years and that none of their animals died of ingestion. However, impaction with sand is likely and can be fatal to your pet.
If your pet comes from hot place and loves burrowing, you can make a mix of playsand (60%), topsoil (20%), some clay and topped with granite rocks (optional) or similar. While the impaction risk is still there, it is better than using pure sand.
Never use sand for hatchling and baby reptiles, as they are much more likely to ingest it. If choosing sand, finer sand is a better choice than coarse sand. Don’t use sharp silica sand, construction or unwashed sand. Always consider mixing some sand with other substrates, and avoid using on its own.
Bad substrate options
Type 1: Walnut shells
Walnut shells is a bad substrate to use for your pet. It poses a high risk of impaction and can cause serious injuries externally or internally if ingested.
Type 2: Sawdust
Sawdust is a bad substrate for your exotic pet. It is dusty and can cause respiratory issues. Avoid using altogether.
Type 3: Coniferous tree shavings
Substrate made from coniferous trees, including pine, cedar (the worst), spruce, larch and others must not be used in a reptile cage. That’s because they contain oils that are dangerous for reptiles, and will over time cause respiratory problems and even skin lesions.
Type 4: Rocks or gravel
Gravel or rocks, is not a good substrate for a reptile. That’s because rocks are hard to move on, and can be ingested. If ingested, they will cause impaction. Gravel might be recommended for some other exotic pets, but please research pros and cons before making a decision.
Type 5: Corn cob or oats
Corn cob or oats are bad substrate/bedding options for exotic pets. That’s because they can expand greatly in a stomach when in contact with water. If ingested, it will expand in a stomach, causing digestive issues and even impaction.