The nocturnal primate from Madagascar that uses a long, thin middle finger to extract grubs is the aye-aye.
The aye-aye (Daubentonia madagascariensis) is a highly distinctive lemur and the world’s largest nocturnal primate. It is native to Madagascar, where it spends much of its life in the forest canopy. Its large eyes help it navigate at night, while continuously growing incisors allow it to gnaw into wood.
Its unusual feeding technique is called percussive foraging. The aye-aye taps rapidly on branches and trunks, listening for hollow spaces that may contain insect larvae. It then bites a hole in the wood and uses its remarkably narrow third finger, equipped with a hooked nail, to pull out grubs.
The aye-aye is sometimes mistakenly called a rodent because of its teeth, elongated fingers and bushy tail, but it is a primate related to other lemurs. It is also not simply another kind of lemur with a long nose: its specialized finger, perpetually growing incisors and nocturnal lifestyle make it one of Madagascar’s most unusual mammals. Cultural fears have contributed to persecution in parts of its native range.