Mealworms (or Tenebrio molitor ) are insects commonly used as food for insectivorous reptiles, such as lizards, geckos, and chameleons. These worms are a rich source of protein and fat, although they have a relatively high fat content, meaning they should be fed in moderation to avoid obesity in reptiles. Mealworms are easy to raise, and their small size makes them suitable for a wide variety of reptiles. To maximize their nutritional value, it is recommended to feed them before offering them to animals, a practice called "gut-loading."