Leopard geckos are carnivorous lizards who consume a wide variety of invertebrates and small vertebrates in the wild. In captivity, leopard geckos thrive on a diet of crickets, mealworms and roaches, although you can offer them super worms, wax worms and silkworms as an occasional treat.
Leopard geckos often attempt to eat prey that is too large, and this can cause them to choke or suffer internal damage. Meanwhile, inappropriately large insects may bite, scratch or intimidate your pet. Provide your leopard gecko feeder insects that are about as long as the space between the lizard’s eyes.
Unlike warm-blooded animals, which must eat often to power their high-speed metabolism, leopard geckos do not need food every day. Leopard gecko breeder Ron Tremper recommends feeding your pet two appropriately sized insects for every inch of your pet’s length, four times per week. For example, a 5-inch-long leopard gecko requires 40 crickets, mealworms or roaches weekly. Because leopard geckos are nocturnal lizards, offer your pet food right after you turn off the cage lights.
Remove any uneaten crickets from the cage promptly. Crickets allowed to roam freely may spread parasites or pathogens via their droppings, and they may chew on your lizard’s delicate skin.
To counteract any nutritional deficiencies in your pet’s prey, dust the feeder insects with a vitamin powder. Over-supplementing your pet’s food can be just as dangerous as a nutritional deficiency, so consult your veterinarian to determine a proper schedule. Additionally, to ensure that females and growing juveniles have enough dietary calcium, most keepers leave a dish of calcium powder in their geckos' cages. The geckos consume the powder as necessary to remain healthy.
Additionally, it is wise to “gut load” feeder insects before offering them to your lizard -- provide the bugs some dark leafy greens, whole grains, carrot slices and a piece of an orange. After eating these foods, the insects will be full of vitamins and minerals important to your pet's health.
While wild leopard geckos may eat small lizards, frogs or snakes from time to time, these food items are inappropriate for captive geckos. Some keepers offer newborn mice to adult female leopard geckos, but most authorities recommend against this practice. In addition to being high in fat, newborn mice are calcium deficient, as their bones and skull have not yet hardened.