A hippo sleeping underwater automatically rises to the surface every ~4 minutes and breathes without waking.
23
In 1918, a homing pigeon saved over 190 American soldiers by delivering a message to nearby support despite having been shot through the breast, blinded in one eye, covered in blood, and with a leg hanging on by just a tendon.
22
The male seahorse carries babies and 'gives birth' to them instead of the female.
7
A newborn Chinese water deer is so small, it can (almost) be held in the palm of a hand.
13
Parrotfish make themselves a kind of mucus 'sleeping bag' which masks their smell from predators and keeps parasites away.
4
Ants have tiny magnetic compasses in their antennae which help them navigate.
9
The cat brain weighs about 30g.
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