But what do they see?
What science can tell us about how other creatures experience the world
A Greek doctor found himself unable to experiment on humans when he came to America, so he used animals instead.
In the 1980s, one young scientist solved the mystery of how animals without mouths and guts manage to feed themselves.
After a Vietnam veteran encountered a grizzly bear in Yellowstone, he pledged to dedicate his life to protecting the animals.