Sometimes, younger monkeys can be partially potty trained, but they lose that ability as they mature. In addition, as they're attempting to potty train, they tend to throw their poop and play with their pee. Because of this, pet monkeys have to wear diapers throughout their lives.

Why do capuchin monkeys wear diapers?

Capuchin monkeys will mark their territory by urinating on it, so most owners of capuchin monkeys prefer to diaper train them.

Do monkeys stink?

Sorry if that offends you, but monkeys stink! Marmosets in particular have a musky scent that is very off putting to humans. And don't even think of keeping them inside. They'll throw poo, urinate all over the house and make a massive mess as they do so - and that's all normal behaviour for a wild animal!