How many muscles does a dog’s ear have, what is a group of pugs called, and why do cats meow? Read on to find out. 1. Cats have a resting heart rate of 140-220 beats per minute. Small dog breeds average 100-140 beats per minute and large dog breeds clock in at 60-100, just like the human heart. 2. Dog ears contain about 18 muscles, allowing them to raise, lower, rotate, tilt, and move them independently so they can hear better and express emotion. 3. Cats have 32 ear muscles, which allow them to swivel and rotate to pinpoint the source of a noise. They can also move each ear independently and rotate them 180 degrees. 4. A group of pugs is called a “grumble.” Some say this comes from mopperen, Dutch for “to grumble,” which makes sense since the Dutch word for pug is mopshond. 5. When cats walk, their front and back legs move in tandem on the same side — back right, front right, back left, front left. Giraffes and camels also walk like this. 6. Cats have about 470 taste buds, while dogs have 1,700. By comparison, the average human has 9,000. 7. The average dog can run 15-20 mph. The fastest breed? The greyhound, which can reach up to 45 mph. 8. Cats spend almost a third of their waking hours on grooming. 9. A dog’s sense of smell can decrease by up to 40% when he’s overheated. 10. Cats only meow at people, not other cats. They’ve evolved to communicate this way with humans because we can’t understand the typical way they communicate with other cats — through scent, facial expression, and body language. Kittens, however, will meow to their mother to get her attention, but they stop once they’re grown. Want to learn more? Check out 15 more fun facts about cats and dogs.