The game simulates two opposing ant colonies. The player takes control of a lone ant, highlighted in yellow. They can use this ant to find food, dig tunnels, move small pebbles and food, and leave pheromone trails to "talk" with fellow ants. They can attack predators (spiders, caterpillars, and ant-lions) and opposing red ants.
The object of the game is to drive the humans out of their house and defeat the red ants. Their house and yard are divided into a group of several dozen squares, which must be individually won. In order to win a map, the area must be clear of red ants. Giving birth to Queen ants allow the player to "colonize" other map squares.
Unfortunately, the predators and red ants aren't the only risk to being an ant; lawnmowers, footsteps, and rain are among the threats to your ants survival.
Black ants, red ants, spiders, pill bugs, caterpillars, antlions, and birds are all the creatures in the game; however, there is a human, his dog and an occasional cat for comic reasons on the yard/house map. The human is a hazard when he operates the lawnmower or steps on a square with an ant colony.
- Spiders appear only one at a time and eat any ant on sight. Spiders can only eat one ant at a time and are faster than any other creature including the player's ant. Spiders can be killed and become food if enough ants surround it. When the ant population gets high enough, the spider starts shooting red lasers from its eyes to kill ants (this is actually thought to be spider venom as some spiders do shoot venom).
- Ant-lions live in small pits and eat any ant that falls into their traps. An ant-lion can be killed if enough ants surround it.
- Caterpillars move in a straight path, and can only be stopped if an ant crosses its path. Caterpillars can also be killed for a substantial amount of food if enough ants surround them.
- Pill-bugs just move around the area doing nothing useful and cannot be easily killed due to their armor. They cannot be killed at all in the game.
- Birds eat drones and young queen ants in the air. They appear only in the whole-yard view when drones and queens are flying (after mating, but before sending them to new map squares).
- Humans can be seen walking around, sometimes mowing the lawn, possibly killing ants.
The player can also switch into the role of the spider. As a spider for example, one may move around and kill opposing ant colony members. This adds an interesting twist to the game.
The ants' caste system in the game is simple. Workers normally make up most of the colony and their jobs are to find food and bring it back, dig up the nest, and to care for eggs, larva, and the queen. They also help defend the nest. Soldiers are stronger than workers at fighting other ants and can do most of the same jobs as workers but need more food and can't care for eggs and larva. The queen ant only has to lay eggs and is the most important ant. New queens and males (drones) have wings and their only job is to mate and make new colonies.