Only one open mouth event was recorded when a dolphin was playing alone, but they recorded 1,288 open mouth events during social play sessions. A total of 92 percent of these expressions happened ...

Zoomarine, Italy Bottlenose dolphins “smile” at each other while playing, making open-mouth facial expressions that are similar to those used by other animals, new research suggests.

image: Open mouth smile view more Credit: ZooMarine, Italy Dolphins are extremely playful, but little is known about how they—and other marine mammals—communicate during playtime. New research ...

Scientists have long known anecdotally that dolphins can display a behavior called “open mouth,” which people often associate with a smile. Other animals, like primates, can make a similar ...