At the turn of the 20th century, a famous horse named Clever Hans toured Germany. The horse stunned crowds as his trainer demonstrated the animal's alleged ability to understand German, tell time and ...

Socrates, a great philosopher, speculated that without verbal or written language, one could communicate using sign language. Little did he know that more than 2,000 years later, animals would be able ...

Sophie Cohen-Bodénès knew she was onto something when she saw the cuttlefish extend two arms upwards while twisting its six others together. It was making what she calls the “up” sign – and, ...