Plus, researchers could hear adult howler monkeys calling back and forth with the infants, who would sometimes try to crawl ...

Researchers have discovered a weird, new behavior among capuchin monkeys, and it involves kidnapping howler monkey infants.

Credit: Christian Ziegler/Brendan Barrett / Max Planck Institute of Animal Behavior/Cover Images A capuchin monkey named ‘Joker’ has sparked a bizarre and cruel fad among his kind on an island off the ...