Pet Desert Beetle Care Sheet

As mentioned previously, desert beetles are communal and that means that different species can be kept in the same tank together. They get along and their care needs are similar.

The kind of tank or enclosure or terrarium you keep them in will be based on a few things.

Quantity of Beetles/Size of Tank

I'm often asked how many beetles can live in a particular tank. Only the dimensions of length and width matter, since the beetles don't really occupy the airspace of the tank in the vertical direction, except sometimes to climb on decor you put in the tank. Also, spacing is in the eye of the beholder and so some people prefer lots of beetles moving around all the time, interacting with each other, while others like a more "Zen" look, where things are calm and more quiet and the bunches of beetles aren't traversing the sand in the tank that you spend an hour every day combing with that little rake thingy.

But seriously, it's hard to give people a number and it depends in part on how much "decor" you have in the tank and what kind of decor it is. For example, a branch of some kind might offer some climbing options to the beetles, but it might be only touch the ground a little bit in a couple spots. This doesn't reduce the floor space of the tank in any appreciable way, which could mean more beetles. But then again, a slab of bark will cover the ground to a greater degrees, and yet you will often see your desert beetles huddled beneath it in larger numbers, and so this type of decor may encourage them to take shelter. But a big rock, for example, with the same footprint as the slab of bark will not allow the beetles to get under it and so this type of decor will reduce the "living space' in the tank to some degree. And so what you put in there affects how many beetles will be appropriate for the tank, but keep in mind that your own subjective feelings and aesthetics about spacing and balance will uniquely dictate what "looks right" to you in terms of the quantity of pet beetles you have in the tank. Trust me, the beetles never complain! 😉

Substrate

In general, all the desert beetles we offer on this website are happy on a substrate that is a mix of sand and soil. When people write me to ask about particular brands of soil, I tell them I'm not familiar with that brand and partly because the ingredients in the very same brands can vary from region to region. And even if I've tried the brand for the region I live in, not all bags are alike with respect to ingredients and this is particularly true for brands that say that there are recycled ingredients, like compost, in the bag. You just never know what you're going to get.

But in general, you will be fine if you purchase organic soil of any kind, as long as the label doesn't indicated that there are added chemicals for fertilizers. READ THE LABELS!

As for sand, it doesn't matter too much. Please keep in mind that some sands contain silica dust and this can cause lung problems. You might wear a mask while you are working with it but the concerns here are mostly when you are dumping it in the tank or mixing it with soil, when that dust is airborne. I don't personally but I am thoughtful about how I work with the sand and I always work with it outdoors. One other thing to mention about sand is that some pet store brands are hydrophobic, which means two things. First, it repels water and if you add any water into the sand it will just ball up on the surface and won't be absorbed. I don't like that. Plus, any beetle that walks by is going to have the water and sand adhere to them. The other issue with it is that it is super fine, almost like a powder, and it will stick to the beetles through static electricity or other adhesive properties that a physcist can explain to you.

Truth be told, most any substrates are fine for the beetles but I tend to like that mix of sand and soil. I've used coconut fiber in the past as an ingredient but if that is your main ingredient, you will find that it is too loose and the beetle will have trouble getting a footing as well as they would in a sand-based substrate. And besides, the beetles just look cool on sand. So sand it up!

Ventilation

A moist environment with little ventilation is not a healthy environment for these beetles, most of which come from and are adapted to arid, desert lands. But that's not to say these beetles are out cruising around under the hot desert sun. No, most of them find cooler places to pass the day, like under rocks or in rodent burrows. These hiding spots tend to be cooler and a little bit more humid, but during the cooler hours of the evening and then through to the morning hours, these beetles are out and about, foraging for food and looking for mates during breeding season.

So, we can't talk about ventilation without talking about temperature and humidity. This triad is key for every terrarium that will house any kind of organism.

In nature, desert beetles experience the seasons. They are more active on warmer evenings than they are on cooler ones. And they will generally spend the winter months completely underground for months on end. But no keepers want to go that long without seeing their pets and so it's never winter in the terrarium!

With respect to temperature, if you are comfortable with the temperatures in your home, the beetles will be fine. I'll say it again because you have a little anxiety on this point. They will be fiiine! You don't need to offer them supplemental heating above and beyond what you are doing for yourself to feel comfortable in those colder months. That doesn't mean you can't, and it doesn't mean you shouldn't. It's for you to decide and again, warmer beetles are more active beetles. And active beetles tend to be more entertaining. Common methods used are a metal-screended lid with a low wattage bulb on top. Care must be taken if you use this method not to burn your whole house down, and you must be exceptionally careful that you test out how hot various surfaces in the tank are getting before you put the beetles in. To do this you'll need a small thermometer. Sticking it to the side of the tank does nothing. Beetles can't climb glass or plastic.

The life cycle of desert beetles, tenebs, is the same as it is for other beetles: egg, larva, pupa, adult. When an adult beetle goes through complete metamorphosis from larva to adult, it emerges from the pupal phase and is temporarly a very pale-looking adult. Its body is soft and it takes a few days to harden and darken to the normal, adult coloration. During this time it is known as a teneral and it should be left entirely alone so that it isn't damaged or injured.

We'll work through the life cycle in reverse order, starting with adults as that is the stage where most people are introduced to tenebs.

Adult tenebs are the life stage most people are familiar with. They look like beetles, to put it as simply as possible.

Larvae (plural, and the singular is larva) tend to be pale and are usually orange in coloration. The most familiar teneb larvae are your basic mealworms (Tenebrio molitor) that are commonly found at pet stores in the feeder section. This is the one beetle species in the pet trades that is more familiar for the larval form than for the adult form. But the adults actually make decent pets.

Larvae grow through molting. When they hatch from the eggs they begin to feed. When they eat enough and a bit of time passes, they reach a point where they need to shed their exoskeleton in order to get bigger. For the common yellow mealworm beetle from the pet store, they may molt 10 to 20 times before they pupate and then emerge as adults. There is some variation in the number of molts, even within a species.

The pupal stage is where the larva metamophoses from larva to adult. It is during this time that the insect completely changes the shape of its body in a miraculous way. Science is still trying to catch up with how this works, exactly, but they'll get there. All the tissues break down in the larva and reconfigure themselves into the shape of a beetle. You can see the various parts of the beetle begin to take shape. After 1 to 4 weeks, depending on species, parts of the pupa darken and then the rest of the beetle darkens and within a few days the adult beetle emerges. It is a teneral (soft and pale) for up to a week before it looks and acts like a normal beetle.

Eggs are laid in the substrate. Some species are very easy to reproduce in tanks while others do much better in nature, like blue death feigning beetles. With the correct methods, most of the pet beetle species in the hobby can be reproduced.

Desert beetles are very active bugs, compared with mantises and tarantulas, for example, and in nature will spend their time wandering in seemingly tireless fashion, searching for food. In hotter places they are unlikely to emerge before the sun dips down past the horizon and to some degree this tendency is mirrored in your pet tank. In nature, the ground immediately begins to cool off more quickly as the sun goes down and the beetles come out from under rocks and other debris on the ground, or burrows of various kinds, to pass most of their active hours looking for food. In the desert, food can be a little scarce but they've made a living doing it for millions of years.

As such, they turn out not to be picky eaters. The first thing you should know about what to feed them is have fun experimenting! Really, this is just a fun perspective to have. If you have little bits of this or that left over from your own meals, offer it to the beetles. Let your own curiosity run wild and see what happens! If you have a dog or cat or fish, by all means, offer them some of their dried food and see what they like and what they don't. I once offered them flour tortillas and bagels. They wouldn't touch them. It made me think think these foods may not be good for me, either. Same with onions, no takers.

People are often surprised by how little the beetles eat, and usually this is an artifact of the general human tendency to put more food in the cage than the beetles are interested in eating. And if there is food in the tank all the time, it doesn't look like the beetles are touching it. Certainly, it is better to offer too much than too little, but finding a nice balance for the number of beetles in your tank, in combination with fine tuning the amount of food you offer, is an exercise worth undertaking.

As a general rule, we provide them with some kind of produce and usually for us that means bits of carrot and apple. We always peel all fruit and vegetables that grow above ground, like cucumbers (which are really fruits since the seeds are on the inside). Tenebs are very sensitive to pesticides on produce, including fruit and vegetables and this includes organic vegetables that are treated with so-called organic pesticides. At the very least give a good thorough wash to any produce you are going to feed to your beetles and peeling everything is a good insurance policy.

Supplemental drinking water is not necessary for your desert beetles if you are feeding them even fairly small amounts of produce on a weekly basis. If you have a heat lamp or heat pad on your tank, hydration is slightly more important, even for beetles adapted to truly dry areas, like death feigning beetles.

Protein! Those dry pet foods for your mammalian or aquatic pets that are protein-based are great options for feeding to your beetles. You may find that if you offer small enough piece, the beetles carry them off and can eat them individually. We like to use small fish food pellets. Your desert beetles love protein-based foods and so they should always be offered, but that's not to say that you can't provide them with vegan-based protein options if you are so inclined.

You can scatter the food on top of the substrate or put it in a small dish. It's up to you. If you are offering them something wet, like the jelly cups that are very popularly offered to these beetles, it's best to put these in a little dish (or milk cap, for example). This will keep the sand and soil from getting caked up by the moist foods and the foods themselves from getting sandy as the beetles come and go.

Offering whole, natural foods is best. Foods with additives may or may not shorten the lives of your beetles, but I think it is fairly intuitive that natural diets are best. And with that said, one of the primary diets of these beetles in nature is other dead insects. In summer months, moths and flies emerge by the millions and all eventually meet their end where they fall and are scavenged by other insects like desert beetles. And the planet stays rather clear of dead insects because scavengers are always busy at work, keeping the order!