Some older/less efficient worker termites will develop 'backpacks' of toxic chemicals that explode when the termite is threatened. They are essentially used as suicide bombers when the colony is being attacked.
8
Crows living in some urban areas drop nuts into traffic to let the passing cars crush them, then they wait for the red lights to stop the traffic so they can grab and eat it.
17
Dolphins have names for one another.
18
The octopus does not have a blind spot.
273