Nocturnal and generally slow and sluggish, nurse sharks spend much of their time resting on the ocean’s bottom. They tend to rest in groups during the day, with up to 40 individuals piled on top of one another, and hunt alone at night. Unlike many sharks, this species is thought to be non-migratory—the nurse shark adapts to cold by becoming even less active!

The nurse shark is light yellowish-brown to dark brown, and some have small dark spots. It has a flattened body and a broad, rounded head with two conspicuous barbels between the nostrils, which it uses to find food. A nurse shark’s mouth is filled with rows of small, serrated teeth for crushing hard-shelled prey. Although they’re docile and mostly harmless to humans, they’ve been known to bite in self-defense.