Which New World monkey is famous for using stones to crack open nuts?

The New World monkey famous for using stones to crack open nuts is the capuchin monkey. Several capuchin species place hard-shelled foods on a stone anvil and strike them with a stone hammer, exposing the edible seed inside.

This behavior is a striking example of primate tool use. Capuchins also use sticks to probe for insects, dig for roots, and extract honey. Their dexterous hands, strong grip, intelligence, and varied diet help explain why they are among the most accomplished tool users outside the great apes.

A common mix-up is assuming that every capuchin uses stones in the same way. Stone-tool use is especially well documented in robust capuchins, including black-striped and bearded capuchins, and can vary between populations. Spider, howler, and squirrel monkeys may manipulate objects or use tools in limited contexts, but the classic nut-cracking image belongs to capuchins.