When eight capuchin monkeys decided to make a break for it at the zoo in Parana, Brazil, they used the tools they had at hand to open the door of the cage. (Another example of how the old conventional wisdom that “using tools is a uniquely human ability” is completely wrong.)
The monkeys used a stone tool to disable the lock on their enclosure, and quickly took off into the adjacent forest.
Three of them were soon recaptured in a trap baited with tasty fruit. But a fourth left the forest, headed into town, and was found in a restaurant the next day. On Treehugger, Stephen Messenger writes:
Capuchin monkeys are thought to be the most intelligent of the New World monkeys, exhibiting a remarkable ability to use stone tools. Researchers have observed capuchins in the wild gathering rocks, often collected from great distances away, to help them to crack open hard nuts. This skill is passed on generationally as younger monkeys learn by watching their elders.
Applying this same tool usage to the novel task of breaking locks, however, indicates an extraordinary use of logic to solve the unnatural dilemma of their captivity. But what’s more, perhaps, is the fundamental desire which guided their actions: the longing to be free.