Published January 13, 2012 12:00AM
A group of eight capuchin monkeys used rocks to smash a lock and escape from a zoo in the Brazilian state of Paraná earlier this week. Zoo staff have captured four of the eight escapees, one of which was discovered when it wandered into a local restaurant. Capuchin monkeys have been observed using rocks as tools, often to crack nuts, but using a rock to escape suggests unusually advanced cognition.
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