Whales and dolphins are mammals, not fish. Scientists thing they are as smart as humans! -Humpback whales communicate by singing songs -A dolphin sleeps with only half its brain at a time -The beluga is the only whale that can swim backwards -The largest animal on earth, the blue whale, can't swallow anything larger than a beach ball -A sperm whale can hold its breath for more than two hours.
About the author
Erin is a biologist that travels the world researching whales, dolphins, marine mammals, fish and creatures of the rainforests. She has twin daughters.