Take your pick: Aye-aye joins ranks of snot-eaters
When scientists caught the aye-aye on video using its strangely thin, eight-centimetre-long middle finger to deeply pick its nose, it pointed towards a larger mystery: why exactly do some animals eat their own snot?. The middle fingers of aye-ayes are not only long and thin, but also have a unique ball and socket joint they use to knock on wood to locate grubs.