Contrary to what many people may think, animal protein is quite harmful to iguanas. Crickets will not necessarily harm an iguana a great deal unless fed to them on a regular basis, however since these reptiles are herbivores things such as crickets are not a necessity within their diet and would be better off just being avoided altogether. The important thing is to make sure that your iguana is getting enough calcium and nutrients. Some pet owners have been known to give their iguana, crickets once a week that are covered in a calcium dust to help add an additional amount of calcium to their diet but as mentioned before, iguanas are better off not eating insects or other food sources that include animal protein.
Iguanas in the wild are herbivores that only eat mature leaves of trees as well as some flowers, fruits, and berries. This diet is difficult to reproduce with iguanas who are kept in captivity because many of the plant varieties in different climate areas are actually toxic to the reptile. This is a lot of misinformation available about what iguanas eat which can lead to premature death in these marvelous creatures.
This is why it is so important to understand a few factors when considering an iguana’s diet and its physiology. An iguana’s teeth are designed to clip off leaves, not to chew or bite, due to this fact, food must be chopped up very small. To maintain good health, an iguana also needs a careful balance of calcium and phosphorous with a 2 to 1 ration. Iguanas who are not given this correct balance often are diagnosed with metabolic bone disease and is a common case of death in many captive iguanas.
The bulk of this creature’s diet should consist of greens such as turnips, collard greens, mustard greens and/or dandelions. Other non-staple greens that can be used from time to time include kale, spinach, chard, and carrot tops. However these should be fed sparingly and in moderation. Fresh vegetables such as green beans, squash, peas, asparagus, carrots, and parsnips are great for iguanas. Avoid regular feeding of things such as broccoli, cauliflower, brussel sprouts, mushrooms, etc. these are better served as a treat from time to time.
Wild iguanas eat little fruit as too much fruit can be the cause of diarrhea. Citrus fruits such as tomatoes, grapefruit, and oranges are too acidic for the iguana and should be fed only on rare occasions or not at all.