Dolphins are extremely playful, but little is known about how they -- and other marine mammals -- communicate during playtime. New research shows that bottlenose dolphins (Tursiops truncates) use the ...

Dolphins are known for what appear to be big, contagious smiles. But do they actually, well, smile? The answer, according to a new study of dolphin play, is a resounding “maybe.” Dolphins use their ...

Dolphins living in captivity often make an open-mouth facial expression while playing with each other. Zoomarine, Italy Bottlenose dolphins “smile” at each other while playing, making open-mouth ...

Some animals appear to smile. But the emotion behind the smile can be tricky to decipher. Other than the sloth, whose smile is pretty much permanently attached, the non-human animal most associated ...