Chameleon is taking bites out of the leaves in the cage.
Meaning: A small number of chameleon species will take bites out of the leaves in their cage. The Veiled Chameleon is the best known for doing this. We don’t know exactly why they do this. Hypothesis include getting moisture form the leaves or some base nutrition. These do not make sense because the environment where the Veiled chameleon comes from is quite moist and there is amble insect prey that are much more nutritious than plant matter. The videos showing veiled chameleons in arid, barren land is when the dry season hits and kill the food, the leaves, and the Veiled chameleons. These videos and pictures are not showing how they live.
The best explanation from from Petr Necas, who observed them in the wild. He postulates that they are taking a bit of leaf for roughage to help the digestive system. With a large component of their juvenile diet being caterpillars there needs to be roughage to help the mass move through the digestive system. Thus the finding of poop with undigested leaves wrapped around and in it.
Veiled Chameleons are insectivores/carnivores and do not need fruits, vegetables, or leaves for their health. They get the necessary nutrition through the insects and the sweets fruits could actually cause issues internally.
There is no danger in your Veiled Chameleon taking bites of leaves. Though, this is a point where we need to think about whether there are any plants that are poisonous to chameleons. Currently, we know of none. Pothos and Schefflera (Umbrella Plants) are on the dog and cat poison list due to having oxalates in their leaves. Oxalates are pointy crystalline structures that irritate the throats of dogs and cats, but they appear to have no effect on chameleons.
Plastic plants are also an issue for Veiled Chameleons due to the potential of them biting a piece off and swallowing it. Though, they would probably pass a small piece without issue, there could be any number of complication that ensue. Thus it is safest to use on live plants in the chameleon cage.
The plant section on the Chameleon Academy is specifically designed for chameleon husbandry and the plant lists are of plants that have been tested in chameleon cages. There are specifica plants which are labelled as “Veiled Approved” which identify the plants that community members have seen Veiled Chameleons takes bites from and show no ill effects. This does not mean the other plants will harm a chameleon, just that I have not collected an eye witness that they have eaten the plant.
Check out this page for plant information for chameleons.