The aye-aye is the lemur that uses an elongated middle finger to find grubs in wood.
This unusual nocturnal primate has a specialized feeding technique called percussive foraging. It taps tree branches with a slender finger, listens for changes in sound that may indicate a hollow, then gnaws through the bark with continuously growing incisors. Finally, it uses the long, flexible middle finger to pull out insect larvae.
The aye-aye’s large ears help it detect sounds, while its prominent eyes support nighttime activity. Its hands also have an unusually narrow, elongated third digit, although the fourth finger is longer overall. This combination of tapping, gnawing, and probing is unique among living primates.
Aye-ayes are native to Madagascar and spend much of their lives in trees. Their strange appearance has contributed to folklore and misunderstanding, but they are genuine lemurs, not rodents. Habitat loss and hunting have made conservation a serious concern for the species.