The aye-aye (Daubentonia madagascariensis) is a lemur, a strepsirrhine primate native to Madagascar that combines rodent-like teeth and a special thin middle finger to fill the same ecological niche as a woodpecker.
It is the world's largest nocturnal primate, and is characterized by its unusual method of finding food; it taps on trees to find grubs, then gnaws holes in the wood using its forward slanting incisors to create a small hole in which it inserts its narrow middle finger to pull the grubs out. The only other animal species known to find food in this way is the striped possum.
From an ecological point of view the aye-aye fills the niche of a woodpecker, as it is capable of penetrating wood to extract the invertebrates within.
The aye-aye is the only extant member of the genus Daubentonia and family Daubentoniidae (although it is currently classified as Near Threatened by the IUCN); a second species, Daubentonia robusta, appears to have become extinct at some point within the last 1000 years
The aye-aye commonly eats animal matter, nuts, insect larvae, fruits, nectar, seeds, and fungi, classifying it as an omnivore.
Aye-ayes are particularly fond of cerambycid beetles. It picks fruit off trees as it moves through the canopy, often barely stopping to do so.
An aye-aye not in its natural habitat will often steal coconuts, mangoes, sugar cane, lychees and eggs from villages and plantations.
Aye-ayes tap on the trunks and branches of the trees they visit up to eight times per second, and listen to the echo produced to find hollow chambers inside. Once a chamber is found, they chew a hole into the wood and get grubs out of that hole with their narrow and bony middle fingers
The aye-aye was thought to be extinct in 1933, but was rediscovered in 1957. Nine individuals were transported to Nosy Mangabe, an island near Maroantsetra off eastern Madagascar, in 1966. Recent research shows the aye-aye is more widespread than was previously thought, but is still categorized as Near Threatened.
As many as 50 aye-ayes can be found in zoological facilities worldwide.