Viper Geckos are insectivore geckos that live in arid, sandy regions in Pakistan. Consequently, their main food sources both in the wild and in captivity should consist of crickets, locusts, roaches, and mealworms. Like with most reptiles, these feeder insects should be gut-loaded with healthy vegetables as well as dusted with a calcium and vitamin D supplement powder before being fed to your Viper Gecko.
A healthy Viper Gecko Diet
There are three main concerns with a healthy Viper Gecko diet: That they get enough calcium (critical for bone health among other things), that they get a healthy ratio of protein to fat (to prevent obesity), and that they don’t choke or get impacted from their food sources (as these geckos are quite small).
Like most insectivore geckos, Viper Geckos need quite a bit of calcium to maintain their bones, limbs, and for other important bodily functions. In the wild, mineral deposits and the insects they hunt are the main source of calcium. However, many wild geckos are actually malnourished, which is one of the reasons why they live two to three times longer in captivity. Feeder insects alone don’t provide enough calcium, which is why it needs to be supplemented. (more on that in a bit)
Like most animals, Viper Geckos need protein for energy/calories, especially since they move around quite a bit. Feeder insects tend to be high in protein (which is why there is a growing trend of using these as a protein source for human consumption, too!). However, some are relatively high in fat – especially various worms. Since the gecko will likely still eat until they get enough protein, and many geckos like to over-eat when given the chance, fatty food sources can quickly lead to excessive weight gain.
Finally, because of their small size, many feeder insects that are good for larger reptiles, such as Leopard Geckos, are too large for the small Viper Gecko. Big insects can lead to both choking and impaction in your Viper Gecko, which is why you need to pay close attention to only feed appropriately-sized crickets and roaches, as well as only the smaller, softer worms.
One more thing: While Viper Geckos get most of their water from the air, water droplets they drink from, and their food, it’s still a good idea to keep a small water dish in the tank at all times. A bottle cap is a common choice. The main concern is the depth and size: you can not use a dish that the Viper Gecko can immerse themselves in, as they might drown. Also, make sure to replace the water daily with clean tap water. Don’t use distilled water, as the natural minerals in tap water are important for the gecko, too.
Viper Gecko Food Sources
As insectivores, Viper Geckos eat only insects. In the wild, they eat whatever they can hunt and eat – but in captivity, their diet should be more carefully curated. Exclusively feed quality, commercially-bred insects (no self-caught, wild insects) to prevent infections, injury, or pesticide ingestion.
Some feeder insects can be bred at home, too – mealworms are a great example for that. Most insects should also be fed a healthy diet of things like oats and vegetables to provide important nutrients to your gecko’s food. Remember, the feeder insect is only as healthy as its diet.
Feeder Insects
The two main aspects to watch out for when choosing feeder insects are the protein-to-fat ratio, and the size. The insects on this list are all safe and healthy choices as long as you feed the appropriate size.
Adult Viper Geckos can eat insects up to ¼ inch long (about 6mm), while young Viper Geckos should be limited to ⅛ inch insects (about 3mm). A good rule of thumb is to never feed anything wider than the space between the gecko’s eyes. That is roughly the size of their throat – anything larger can be dangerous.
Crickets are a staple food source for Viper Geckos, but you need to watch their size. Even very young crickets are often too large for juvenile geckos, and they grow too large for adult Viper Geckos within just a few weeks. Additionally, some owners don’t like having loud insects such as crickets in their home – especially if one manages to escape the box.
Dubia Roaches are similarly popular among reptiles and reptile owners, but also quickly grow too large for Viper Geckos. Make sure to find a local store where you can buy them in small quantities while they are very young, as any larger order will go mostly uneaten due to their size.
Locusts can be a little more difficult to get, especially in the USA, but are quite similar to crickets as a food source for your Viper Gecko. Small ones start at around 5mm, so once again, size is a bit of a problem. They quickly reach a size where you cannot safely feed them to your Viper Gecko.
Mealworms are not only one of the most popular staple feeder insects for reptiles and geckos, but also very easy to get, both locally and online. You should offer them to your Viper Gecko right after the mealworm has molded (shed its shell) – at this point, they are the softest. You can recognize this time by their light-tan appearance. Once they become a darker brown, their shell has hardened again. While these worms also grow too large for Viper Geckos somewhat quickly. their soft shell makes them less of an impaction risk than other feeder insects, even at a larger size. However, you should not feed mealworms too much (30-50% of the diet at most) as they have a higher fat content than the previous insects on this list.
Treats: Small worms such as waxworms can be fed occasionally as a treat for your Viper Gecko, but should be fed sparingly as they have a high fat content. You can offer more treats if your gecko seems to be losing weight, already has low weight, or while breeding (for females).
For hatchlings & juveniles: While they are not yet big enough for the larger feeder insects, you can feed your Viper Gecko younglings wingless fruit flies or pinhead crickets.
Fruits & Vegetables
As insectivores, Viper Geckos do not eat fruit or vegetables. When offered, they may nibble and even take bites, but their digestive tract lacks the necessary features to actually digest the cellulose found in fruits and vegetables. In short, Viper Geckos cannot absorb nutrients from eating vegetables, fruits, or greens directly.
Instead, you need to feed these to the feeder insects, which absorb these micro-nutrients such as vitamins, and then pass them on to the gecko when they get eaten.
Supplements
In addition to a healthy mix of feeder insects, you need to supplement with two or three powders:
Calcium and vitamin D should be added to every meal. These often come pre-mixed. A supplement for Leopard Geckos is a good choice, as Viper Geckos are quite similar to those geckos in terms of diet and nutritional needs. To serve this supplement powder, put some of it in a small zip-lock bag, add the feeder insects, give it a good shake to cover the insects with the powder, and then offer the insects to your gecko.
A Reptile Multivitamin should also be supplemented about once a week to once every two weeks – follow the instructions on the packaging for details. Vitamin A is one important vitamin that needs to be included, but a mix of all the relevant micro-nutrients is generally included. If you buy from an established reptile-specific brand, you should not need to worry about the details here.
Calcium needs to be supplemented for bone and tissue health. Metabolic bone disease is usually the consequence of a lack of calcium, and is often fatal for reptiles if not diagnosed very early.
Vitamin D is needed to actually absorb calcium from food, so without sufficient vitamin D, your gecko will become calcium deficient, even if it is supplemented.
Vitamin A is another important vitamin, as it is needed for both skin and eye health in geckos. Especially with their frequent shedding, supplementing vitamin A is important. Vitamin E is also important for skin health, and is generally included in the multivitamin as well.
Foods to avoid
While already mentioned, there are a few food sources that are best avoided to keep your Viper Gecko healthy and happy:
Large insects. Anything bigger than your gecko can safely eat can present a challenge both for eating and swallowing, as well as for their digestion. Impaction – a clogged digestive tract – is a common problem in geckos when eating large, hard insects (mainly the indigestible chitin).
Wild-caught insects. From bacterial infections to herbicides and pesticides, wild insects can carry and contain all kinds of nasty surprises. Don’t feed these to your Viper Gecko. A single insect won’t kill them, but unless you’re living in a very clean, natural environment, wild insects should not be a part of their diet.
Fruits and vegetables. As they cannot be digested by Viper Geckos, feeding plant-based foods is bad for your gecko.
Acidic fruits such as citrus fruits. While many berries, bananas, and apples are somewhat harmless, highly acidic foods such as lemons, oranges, grapefruit, and other citrus fruit are harmful to a Viper Gecko’s digestive system. You should never offer any of these to your gecko.
Sample Diet
Baby and juvenile Viper Geckos, as well as gravid/egg-laying females should be fed daily.
Adult Viper Geckos should be fed every 2-3 days.
A good rule of thumb to follow is to allow feeding for about 15 minutes. Everything that isn’t eaten in that time should be removed from the tank again. This helps prevent overfeeding, as well as leftovers from spoiling, rotting, or live insects from harming your gecko.
It’s also important to not restrict your Viper Gecko’s diet to only one feeder insect. You should offer at least two or three types of feeder insects on a regular basis – not only to make their diet more interesting, but to prevent nutritional imbalances.
Sample Diet for juvenile Viper Geckos
Feed your young Viper Gecko every day. About 15-20 wingless flies or a comparable amount of pinhead crickets or other tiny feeder insects is a good guideline to follow.
If your gecko is done in less than 15 minutes, try increasing the amount of food, or reducing it if there are leftovers after 15 minutes.
Don’t forget to dust every meal with calcium and vitamin D, and about once a week with a multivitamin.
Unlike many animals, young geckos often need more food and especially more calcium than adult ones!
Sample Diet for adult Viper Geckos
You can reduce the feeding frequency to around once every 2-3 days for adult Viper Geckos.
As for the amount, 6-10 feeder insects are a good estimate – depending on the size of your gecko and the size of the insects. Again, observe and adjust as necessary.
Still dust every meal with calcium and vitamin D, and once every 1-2 weeks with a multivitamin.
You can either feed only one type of insect per day and offer different insects on different days, or mix it up a bit and offer variety with every meal.
About once or twice a month, you can also offer some fattier feeder worms as treats. Unless your gecko is underweight, this is purely optional, though.