There's an arms race going on right now between two species of invading ants, the tawny crazy ant and the fire ant. These arch-rivals are currently warring for dominance in the southern U.S., but it now appears the crazies are going to win — the result of a remarkable chemical defensive measure.
One ant sinks in water, but a bunch of them? It turns out they can link together and become an unsinkable life raft. New research shows that when fire-ants are dropped in water, they quickly form a pancake-shaped floating mass, which traps air beneath them.