Nervous dogs wag their tails to the left, and happy dogs to the right (from the dog’s point of view) – and fellow canines pick up on this lop-sided tail language.
10
A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
The sound of a tiger's roar can travel a distance of up to 2 miles (~3 km).
255
The elephant brain weighs about 6,000g.
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