An aye-aye is a lemur found only on the island of Madagascar. It is a nocturnal primate that has large, distinctive ears, long fingers with sharp claws, and a bushy tail. The aye-aye is the largest nocturnal primate in the world, and is known for its unique feeding behavior, where it uses its elongated middle finger to tap on trees and listen for insects inside, which it then extracts using its sharp teeth. The aye-aye is considered an endangered species due to habitat loss and cultural beliefs that associate it with bad luck in Madagascar.