Koko, the western lowland gorilla who learned sign language and became a pop-culture phenomenon, died Thursday morning at the age of 46. The Gorilla Foundation, headed by Dr. Francine “Penny” ...

This is the adorable moment a deaf three-year-old began teaching her 17-month-old siblings sign language. In the cute footage, Amelia Morales can be seen flicking through a variety of animals on her ...

Humans are often thought to be the only animals capable of language. But it’s difficult to prove a negative like this because we’ll never definitively know the subjective interior monologues of other ...