Dogs and Horses Mimic Each Other's Expressions During Play

(Inside Science) — Many animals play. While play may not appear to serve any immediate function, it likely evolved because it can help animals rehearse key behaviors, relieve stress or build relationships, according to Elisabetta Palagi, a sociobiologist at the University of Pisa in Italy. Research on play between species may shed light on how capable each species is of detecting and interpreting playful actions. But up to now, most such work has focused on play between humans and their pets.