Why fish, birds and other animals yawn too, according to an expert
Humans aren't alone when it comes to yawning — all vertebrates do it. But why? An expert explains the likely reason behind this "evolutionarily ancient" act.
Humans aren't alone when it comes to yawning — all vertebrates do it. But why? An expert explains the likely reason behind this "evolutionarily ancient" act.
What's Your Reaction?
