https://www.npr.org/2025/05/19/nx-s1-5395983/baby-monkey-kidnappings-capuchin-howler-culture
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 infants of another monkey species, seemingly just for kicks.
That’s what scientists think after watching a bunch of male white-faced capuchin monkeys walking around with baby howler monkeys clinging to their backs.
The perplexing baby-snatchings, reported in the journal Current Biology, suggest that humans aren’t the only intelligent species with youngsters that pursue apparently pointless activities that can be destructive to other creatures.
https://www.cell.com/current-biology/fulltext/S0960-9822(25)00372-0
Rise and spread of a social tradition of interspecies abduction