Ant researcher Deborah Gordon packs an incredible amount of science into her twenty-minute TED talk from 2003. Discussed: what happens when you dump toothpicks outside the colony; the four jobs worker ants can have; why half of the ants in the colony are just hanging out; what happens when you stick a fiber-optic camera into the colony; how the colony's behavior emerges from a series of simple rules; how colony size changes as a function of colony age (and how you have to dig up all the ants and count them to figure this out). Check it out:

For more, check out Gordon's Lab, Gordon's Wikipedia page, and her book (via Google Books) Ants At Work: How An Insect Society Is Organized. See also: Gordon's TED Talk page.