They also use chemicals to alert other ants. When an ant is squashed, it sends an alarm chemical to alert other ants to attack. This chemical also makes enemies that are attacking the colony attack each other.
I think that ants are the most social creatures out there. They work together to let the colony thrive. They only think about the other members of the colony. I think that if we work together like ants do, the world will be a better place.
http://www.wikipedia.org/
http://theedublogger.com/2010/11/12/share-your-blogging-experience-and-win-big/