NOVA: Extreme Animal Weapons From lobster claws and dog teeth to bee stings and snake fangs, every creature depends on a weapon. But some are armed to extremes that make no practical sense - whether it's bull elks with giant 40-pound antler racks or tiny rhinoceros beetles with horns bigger than their body. What explains giant tusks, horns and claws that can slow an animal down and even impair health... see more