Substrates: Getting your hands dirty!

Before getting into the article proper, I would like to set a couple of things straight here; there is a seeming misunderstanding or really a bastardization of what a vivarium is or isn’t. A vivarium according to the dictionary definition is

a place where live animals are kept under natural conditions for study, research, etc.”


Did you catch the wording there? Under natural conditions. This means both plants and animals from the native habitat you’re trying to imitate are raised together. Personally, I think we do a severe disservice to the animals we keep in a captive environment when we don’t keep them as they’d be found in the wild. When kept under ‘natural conditions’ we often see natural behaviors that are often lost when we keep them any other way. It’s also been theorized and seems completely plausible that when reptiles are kept naturally that they also have better psychological aspect to their being. This is food for thought; I encourage you to replicate the natural habitat of all the animals you keep.

Speaking of bastardized terms let’s talk about ‘herpetoculture’ many are under the impression that Philippe de Vosjoli coined the term ‘herpetoculture’. According to Ken Foose of Exotic Pets Las Vegas it was Tom Huff whom originally coined the term but de Vosjoli was the one who actually got credit for it. The term was coined no matter who you give credit to, to describe the ‘science of keeping live reptiles and amphibians in a captive environment for means other than collecting species for preservation’ apparently this is what herpetologists did at the time.’ Philippe de Vosjoli gave a clearer and what I consider a better definition to the term in Vivarium magazine

“Herpetoculture is an interdisciplinary field which can involve knowledge of herpetology, botany, small-scale open-system design, nutrition, geography, climatology, physiology, veterinary medicine, landscaping, etc.”

Seems, strangely similar to the term of vivarium doesn’t it? Keeping a reptile in a rack system is not herpetoculture, it’s a business decision for monetary gain. Now then, let’s get back to the business at hand. Substrate.


Reptile product manufacturers don’t want me to tell what I’m about to say. I may never see a sponsorship or advertisement from the manufacturers. Then again, I’m not in this to promote things or sell you a product I don’t personally use or endorse. I’m here to educate you based on my decade plus long experience with the facts. Generally speaking, there are three substrates generally speaking, when mixed or used alone can make up just about any needed micro-niche that you might need for most, if not all, captive reptile species kept today.

Listed here are the three substrates for the vivarium.

  • Sand
  • Potting Soil
  • Bark chips


The biggest ‘nemesis’ I never hear the end of, is of course, sand. Sand is a viable substrate to use and one I have recommended for over a decade. I have yet to hear any client ever have an issue when using sand as I have prescribed it to be used. Yet we always hear stories of impacted lizards or other maladies associated with sand being used in the enclosure.

I have somewhat of a theory on why this is. Generally speaking, reptiles will not eat substrate of their own accord. They may occasionally ingest some substrate during feeding, especially insectivores which are commonly fed in their enclosures. Geophagy (the scientific term for substrate eating) is when the lizard purposely eats substrate. I have found evidence that some lizards actually may do this purposefully to aid in digestion of chitinous insect prey.

It would seem that those lizards who are insectivores will also engage in lithophagy which is the eating of small pebbles. (see reference below) While this has only been observed in certain species it is a moment for pause and thinking about what we are feeding and if it’s as close to the wild diet of our now captive animals.

Without digressing too far, before reading the above information; I was of the thought process that the lizards were after trace minerals and possibly calcium. Reason for this was that as customers/clients reported substrate eating (geophagy) my immediate question to them was always the same and so was their reply.

“Are you providing a calcium and multi-vitamin supplement?” I would ask.

“I didn’t know I had to provide that stuff.”

This was followed by a short explanation of why calcium and multi-vitamin supplementation is so very important with our captive squamates generally testudines and saurians outside of snakes. You can read more about this in the article/report Solving the Calcium Conundrum with Dr. Sprackland. After this explanation was made and the customer/client  began providing the nutritional supplementation as directed the reptiles quit eating the substrate. I’m led to believe by these occurrences that in fact the reptile was looking for trace minerals and or calcium so therefore reverted to what is most natural in their wild environment and ate some dirt. This has been further extrapolated from my personal experience with canines and other species behaving in similar fashion when necessary trace elements are missing.

As with any product today whether it be human shampoo or reptile decor there are numerous versions and brand names to select and choose from. Here’s the sticky part where I peeve off manufacturers. With all the brands out there claiming to be the best it’s hard sometimes to cut through the hype to what is real. So I’m here to tell you, personally and honestly.
Washed play sand made by the company Quickrete is the sand type I’ve used for over a decade and never once have any of my animals experienced an impaction related to geophagy. This sand is available from most home improvement stores; often for less than $6.00 for a 50 pound bag. You can buy the other sands found in pet stores; fact is they are much more expensive in comparison to the Quickrete brand that I use. I am not saying that other brands are not good but I have heard numerous complaints and stories personally told to me from those who have used products such as Calci-Sand which is produced by T-Rex. People have personally reported to me as well that there were issues with the other sand substrates as well but I have not personally ever had someone tell me there was an issue with the Quickrete brand.

Potting Soil

It’s been mentioned in almost every Philippe de Vosjoli book I have read wherein there is a need for humidity and a softer substrate than sand. Organic potting soil which is free of perlite would be the equivalent to the coconut coir or expandable bricks of bedding that are sold in most reptile shops. Organic potting soil however is cheaper in the long run as you are buying more material for less money. I have seen 40 pound bags go for $2.47 some of the more ‘premium’ brands will of course cost a bit more but to me this is completely worth it. Especially, if like others you have multiple animals that use this type of substrate.

Bark Chips

This is another substrate which continually gets a bad rap in my opinion. The reason for the bad reputation of this substrate as is usual with most bad reputations in the reptile industry is the promulgation of the rumor that wood chips contain reptile mites. This has become almost a known fact among reptile keepers of all types. There’s a problem however, reptile mites need reptiles to survive. So for those who want to tell me that the bark that I buy from hardware stores which has never come into contact with a reptile carries mites which will infest my enclosures; to you I say ‘horse puckey’ that’s a technical term by the way.

Life Cycle of Reptile Mites

Reptile mites don’t start feeding (sucking reptile blood) until they are protonymphs which occurs with 18-24 hours after hatching. The next week is spent sucking blood, then dropping off into the substrate and molt again into the deutonymph stage. These deutonymphs are non-feeding and molt into the adult reptile mite within 24 hours. Once an adult mite, these vampires are feeding every 4-8 days. A reptile mite can live up to 40 days in the ‘right conditions’ without feeding. Should you get reptile mites see this article

Sara Viernum on how to treat them. Snake Mites ID & Treatment.

Bark Substrate

Just so I am clear, I am not referring to the products often bought in reptile/pet stores. I am referring to what is often known as orchid bark or ground cover bark from the local home improvement center. I use and have used Scotts EarthGro Ground Cover Bark for over a decade now with no reptile mites ever.

“So what does this all mean?”

With all the processing that goes into creating the Scotts EarthGro Ground Cover Bark. I am quite sure that they are not standing around playing with mite infested reptiles. Nor is the bark coming into contact with any reptile mites in its journey to the local Home Depot. With all this said, if and this is a very big if, you buy a substrate product from a location that has had reptile mites you theoretically can bring reptile mites into your collection. Before you run out and burn down your local reptile shop listen carefully. Bagged reptile substrate is generally airtight sealed is it not? So how would a mite get into the bag? There’s the decor we buy reptile mites can live there too, did you know you could bring reptile mites home on your own clothes after touching an infested reptile?

Preventing Reptile Mites

  • Any (non-plastic) decor or bark is baked in the oven 250F for 10min before being used
  • If you come into contact with ANY reptile, before entering your reptile room strip down and shower. Don’t come into contact with those clothes again before they are washed.
  • Any plastic or decor which may melt should be washed in a bleach solution of 1 capful to 1 gallon of water and then rinsed until you can no longer smell bleach.

Benefits of substrates:

Substrates make it easier to spot clean (I only change all of the sand in my enclosures once a month)

Bark and potting soils hold moisture very well and create humidity that you won’t get from paper towels or newspaper.

All of the above substrates are more aesthetically pleasing.

Substrates can be mixed numerous ways to get just the right mix for your species. Searching out where your reptile comes from will help you establish a better way to care for it and may be a very eye-opening experience. To start your research try what we consider the most prolific site for reptile research Reptile Database For example most people think Royal/Ball Pythons come from Africa which is accurate, but they come from no less than 16 different places in Africa with varying environmental niches. The more accurately you can recreate your reptiles natural habitat the better off you will both be.

What substrates do you provide for your reptiles? Share with us on our Facebook Fanpage so we can learn about more substrates.

Reference: 1

Lithophagy and Geophagy in Reptiles

Otto M. Sokol

Journal of Herpetology

Vol. 5, No. 1/2 (May 31, 1971), pp. 69-71