A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
An average cat has 1-8 kittens per litter and can have 2-3 litters per year. During her productive life, one female cat could have more than 100 kittens. A single pair of cats and their kittens can produce as many as 420,000 kittens in just 7 years.
10
The most expensive dog in the world is the Tibetan Mastiff; worth $1.5 million.
2
The oldest recorded elephant lived for 82 years.
213
A 42-foot sperm whale has about 7 tons of oil in it.
209