Owl monkeys, also called night monkeys (genus Aotus), are the only true nocturnal monkey. They are native to Central and South America and they live in family groups with a male, a female, and one or two young. The fathers primarily care for the offspring and they are monogamous. Monogamy in primates is poorly understood (and in humans for that matter.) The male carries the newborn after the first week, and they only return to the female for suckling. They also have a special dedicated personal grooming toe on each foot, they typically weigh just under one kilogram, and they mostly eat fruits (frugivorous) and insects. They're super cute.