The nurse shark is a common inshore bottom-dwelling shark found in tropical and subtropical waters, and its typical habitats are reefs, channels between mangrove islands, and sand flats. Nurse sharks are also nocturnal, spending the day in large inactive groups of up to 40 individuals. Hidden under submerged ledges or in crevices within the reef, the nurse shark prefers specific resting sites and will return to them each day after the night's hunting.