When cats are happy, they may squeeze their eyes shut.
10
When a male gentoo penguin "falls in love" with a female penguin, he searches the entire beach to find the perfect pebble to present to her.
25
Sharks, like other fish, have their reproductive organs in their chests.
248
Cats and dogs can hear ultrasound.
350
Dogs have been man's pet for over 14,000 years.
224
The CIA once spent $20 million on a cat equipped with gear to spy on the Soviets, but it was hit by a taxi.
328
Squirrels forget where they hide about half of their nuts.
698