Extras

Beetles make up the largest group of insects on Earth. Why do so few have massive pincers?
Darwin's Beetles Spar Off

Why Fiddler Crabs Have Giant Claws
Fiddler crabs' large claws look intimidating, but is deadly combat their main purpose?
Why Fiddler Crabs Have Giant Claws

Extreme Animal Weapons Preview
NOVA uncovers the secrets of nature’s battleground—claws, horns, fangs and all.