The hard rigid covering of animals including MOLLUSCS; TURTLES; INSECTS; and crustaceans.

Animal behavior associated with the nest; includes construction, effects of size and material; behavior of the adult during the nesting period and the effect of the nest on the behavior of the young.

Cold-blooded, air-breathing VERTEBRATES belonging to the class Reptilia, usually covered with external scales or bony plates.

Periodic movements of animals in response to seasonal changes or reproductive instinct. Hormonal changes are the trigger in at least some animals. Most migrations are made for reasons of climatic change, feeding, or breeding.

Large, long-tailed reptiles, including caimans, of the order Loricata.