There are more than 3,500 different types of ants found across the world. They live in groups called colonies. Out of these, perhaps the most interesting is the ‘army ant’. It eats living things. The ‘driver ants’ move in armies of thousands of ants. They do not spare any living thing and kill all in their way. Whether a fly or a crocodile, they kill and eat all. The American army ants eat only small living things, like roaches, rats, lizards, mice, etc.