An interesting story of ants I've experienced: when I was in California some time ago standing duty at a barracks, there was an infestation of ants everywhere (anyone in California can guess the type of ants they were). To kill some time I found a can of ant killer and proceeded to spray the ones surrounding a vending machine that they took over. 30 minutes later to my surprise, other ants had found all the places where I had sprayed and cordoned it off with gravel they carried with them as a warning to other ants. Has anyone come across other interesting behavior like this?