A series of studies is described in which some of the sensory and motor capabilities used by the aye-aye, Daubentonia madagascariensis, in foraging for insect larvae are delineated. Although visual and olfactory cues may be of some aid, they are not necessary for successful location of larvae within woody sources. Rather, the aye-aye gently taps on wood surfaces to determine the location of cavities. Although the aye-aye can accurately locate cavities that contain no larvae or those containing inactive prey, significantly more cavities are opened when they contain active larvae. These observations suggest that this primate uses echolocation or a cutaneous sense to find cavities and can also detect the movements of insect larvae within the cavities. © 1991 The Association for the Study of Animal Behaviour.