- Prairie dogs are not dogs. They are a kind of rodent.

 - A frightened dog puts its tail between its legs to cover the scent galnds in the anal area. Since the anal glands carry personal scents that identify individual dogs, the tail-between-the-legs behavior is the canine equivalent of insecure humans hiding their faces.

 - Swans are the only birds with penises

 - Sea otters use so much energy that they need to eat as much as 1/3 of their weight each day.

 - Killer whales kill sharks by torpedoing up into the shark's stomach from underneath