21 Aye-Aye Facts You Didn't Know

By Karin Lehnardt, Senior Writer

Published September 2, 2025

Because of its creepy appearance and unusual eating habits, the aye-aye is considered to be one of the most unique primates in the world._[3]
The aye-aye is the world's largest nocturnal primate._[5]
The aye-aye uses it "witchy" middle finger to hunt for prey in trees. Known as percussive foraging, the process involves tapping on trees and listening to the insects within. When it finds its prey, the aye-aye cuts a small hole with its incisors and then uses its long finger to pull out its meal._[3]
Because Madagascan lore holds that aye-ayes are sign of bad luck, aye-ayes were historically killed on sight. However, because of severe population decline, they are now protected by Malagasy law._[4]

An aye-aye's middle finger is three times longer than its other fingers

Aye-ayes have the largest ears relative to body size of any primate. This trait allows aye-ayes to hear even the faintest noises deep within a tree._[1]
The word "aye-aye" most likely comes from the Malagasy phrase "I don't know." Because aye-ayes were seen as bad luck, this generic name may be a way to avoid referring to it directly._[4]
Unusual for primates, an aye-aye's incisors never stop growing, and their teeth are so sharp that they can cut through cinder blocks._[4]
Aye-ayes are the only living member of the Daubentoniidae family._[4]
While scientists are unsure how long aye-ayes live in the wild, in captivity they can live up to 20 years._[2]
Aye-ayes have been described as a hairy mix between a raccoon and a rat._[7]
Aye-ayes can only be found on Madagascar, which makes the destruction of their habitat even more dire._[7]
According to Sakalava tradition, aye-ayes can slip through thatched roofs and murder sleeping occupants by piercing their aorta's with their "witch" fingers._[6]

An aye-aye's unique middle finger is a multi-tool

Scientists originally thought aye-ayes were rodents because of their appearance, but aye-ayes are actually primates, like humans._[7]
Aye-ayes have enlarged eye sockets to fit large eyeballs, which help the aye-aye hunt at night._[1]
An aye-aye's middle finger has a specialized socket joint that allows it to rotate, much like a human's shoulder. The middle finger also has a hooked nail, allowing it to pierce its prey more easily._[4]

Aye-ayes spend most of their time in trees and sleep in spherical nests high in trees

Because aye-ayes are almost completely arboreal, they seldom touch the ground._[5]
An aye-aye's tail is bushier than a squirrel's and can be twice as long as its body. It is used for balancing and keeping warm, and it may play a role in communicating with other aye-ayes._[5]
When an aye-aye hunts through percussive foraging, it can tap on a tree as quickly as eight times per second._[6]
Because aye-ayes are nocturnal animals and forage alone, there is not an official name for a group of aye-ayes._[5]
Aye-ayes were thought to be extinct in 1933, but, in 1957, they were rediscovered._[6]
An aye-aye's brain is proportionally larger relative to its body size than that of any of its close relatives, such as lemurs and lorises, especially in areas related to touch and hearing. This allows the aye-aye to hunt more efficiently at night.
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