On an island in Panama, a fad that one researcher called "viscerally disturbing" has recently taken off among a group of young male monkeys. These adolescents and juveniles have started to kidnap the ...

Observations of Coiba’s tool-using immature capuchin monkeys show them carrying abducted infant howler monkeys. What is the reason for this behavior? Vanessa Crooks Caught in the act! Capuchin monkeys ...