Monkeys survive predators through vigilance, specific alarm calls, group defence, height and speed. Here is how each defence actually works.
How monkeys court and choose mates, from sexual swellings and consortships to harem takeovers, loud calls and the colour signals of mandrills and geladas.
How monkey families work, from single mothers and helpful aunts to marmoset fathers who do most of the carrying, and why kinship decides social rank.
A guide to monkey facial expressions, from lip smacking and fear grimaces to play faces, and what current research says about monkey emotions.
Where monkeys sleep, why they sit upright instead of lying down, how they stay safe at night, and why sleeping sites are as important as food trees.
Grooming is part hygiene, part social currency and part stress relief. Here is why monkeys spend so much of the day picking through each other fur.
Monkeys do use tools. Capuchins crack nuts with stones, macaques open shellfish, and both learn the skill socially. Here is what the evidence shows.
Can monkeys swim? Most can, a few are genuinely good at it, and some avoid water entirely. Here is what science and field observation show.
Why monkeys have tails, how prehensile tails evolved in a handful of South American species, and why some monkeys have almost none at all.
A species-by-species guide to monkey diets, from leaf-eating colobus and gum-gouging marmosets to grass-grazing geladas and omnivorous baboons.