(Aotus nigriceps) wins the prize for being the most enigmatic. These miniature primates, roughly the size of a small squirrel, hide out high up in the canopy and aid their secrecy, as the name suggests, by being the world’s only nocturnal monkey. They live in family groups and are, unusually for primates, monogamous. Pairs will have just one baby a year – a ball of dense fluff that fits in the palm of your hand and could have been pumped out of a Japanese kawaii factory – all eyes and devastatingly cute.
