Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12
Sloths take two weeks to digest their food.
243
Cats are one of the only animals to domesticate themselves and approach humans on their own terms.
20
Cats and dogs can hear ultrasound.
350
Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16
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