Denmark has twice as many pigs as there are people.
66
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
Cats and dogs can hear ultrasound.
350
In 1949, an official boxing match between a bear and a man was held. The bear won.
41
There was a bear called Wojtek who was adopted by Polish soldiers during WW2. It carried ammunition, wrestled with soldiers, and drank beer.
40
The octopus does not have a blind spot.
273
Alligators can live up to 100 years.
337
A koi fish, named "Hanako", was owned by several individuals over many years and lived to be 226 years old, dying in 1977.
6