With his powerful jaws and sharp teeth, an iguana can deliver an extremely dangerous bite. An iguana is also able to modulate the strength of his bite, allowing him to deliver a careful or playful nip. An untamed iguana is likely to attack when approached without caution.
An iguana has anywhere between 80 to 120 serrated teeth in his jaws. While not all iguanas indicate when they feel threatened, a common sign is the emergence of the dewlap, a flap of skin under his chin that inflates with air to make him look bigger and more intimidating. The pupils of the eyes contract and dilate as the iguana calculates the distance between himself and the threat. When his mouth opens, he is indicating that he is ready to bite. An iguana can move quickly and attack before a human has a chance to react.
If bitten, a person should not yank or remove his hand as this can cause more damage. An iguana typically bites and releases immediately. If he holds on, he should be turned upside down to confuse him or the person should spray his face with water. The wound should be rinsed and disinfected immediately. An iguana's mouth does not typically contain life-threatening bacteria, but good hygiene and standard first aid should always be followed when handling lizards.