Yes, chameleons can bite humans especially during forced or excessive handling or when feeling threatened or territorial. Watch out for hissing as this usually precludes biting. Veiled chameleons are solitary and really do not like being handled too much so it may not make a good pet for children and novice reptile owners. Though they can get used to some handling when tamed early on. Their bite can be painful but it is not toxic or too harmful to humans.