The sound of a tiger's roar can travel a distance of up to 2 miles (~3 km).
255
Denmark has twice as many pigs as there are people.
66
Dolphins have names for one another.
18
Cats and dogs can hear ultrasound.
350
When cats are happy, they may squeeze their eyes shut.
10
Blue whale arteries are large enough for humans to swim through and their hearts are the size of cars.
12