Xantfarm simulates an ant hill and displays it in the root window. Sample snapshot:
There are three Elements in the ant world: Air, Dirt, and Sand. Ants move through Air, dig up Dirt, and drop it as Sand. Ants have three Behaviors: Wandering, Carrying, and Panic. There are a few simple probabilities built in to the program that control the transitions between Wandering and Carrying. To see them Panic, try poking the ants with the cursor.