I just thought i'd throw in that the fire ant mentioned earlier has continued to rampage unchecked across the USA. *In order to attempt to moderate the spread, researchers (my mothers cousin, for one, which is why i know this) spent years doing studies on the potential impact of introducing a native predator of the ants: a small wasp. *Obviously the idea was to prevent the wasp from becoming a further pest. *Anyway, not too long ago approval was given to introduce the wasp into certain areas of the USA.
Since this is a CP forum, i think it will interest my fellow warped people to know that this wasp 'dive bombs' the ants with eggs, trying to stick them to the back of the ants head. *The larvae hatch and burrow into the head, and eventually the ants head falls off, and the critters climb out and fly away, to start it all over again. *Is that gruesome and cool, or what?