When frightened by a predator, Green Iguanas will attempt to flee, and if near a body of water, they dive into it and swim away. If cornered by a threat, the Green Iguana will extend and display the dewlap under its neck, stiffen and puff up its body, hiss, and bob its head at the aggressor. If threat persists the Iguana can lash with its tail, bite and use its claws in defense. The wounded are more inclined to fight than uninjured prey.
Green Iguanas use “head bobs” and dewlaps in a variety of ways in social interactions, such as greeting another iguana or to court a possible mate. The frequency and number of head bobs have particular meanings to other iguanas.
Green Iguanas are preyed upon by hawks and their fear of hawks is exploited as a ploy to catch them in the wild. The sound of a hawk’s whistle or scream makes the iguana freeze and it becomes easier to capture.