Driver ant

Description:

Each colony can contain over 20 million individuals and that qualifies them to "makers of the largest colonies of all the social insects". On the picture there is a soldier class among the workers, with a very large head and pincer-like mandibles. As with most ants, workers and soldiers are sterile (non-reproducing) females. Columns are arranged with the smaller ants being flanked by the larger soldier ants. These automatically take up positions as sentries, and set a perimeter corridor in which the smaller ants can run safely.

Habitat:

Found in an open grassland, with some small scale agricultural areas.

Notes:

Male driver ants are 3 cm long and were originally believed to be members of a different species. They fly away from the colony very soon after birth. When a colony of driver ants encounters a male, they tear its wings off and carry it back to the nest to be mated with a virgin queen. As with all ants, the males die shortly afterward. Each worker ant is only half a centimeter long. The soldier ants which guard the hive are a mere 1.5 centimeters and the queen, the largest of the ants, is from 5 to 8 centimeters long. All driver ants are blind, but they have an acute sense of touch and smell. Larger columns follow scent trails laid down by scouts. The ants eat any animal life they can get their mandibles on. Seasonally, when food supplies become short, they can form marching columns of up to 50,000,000 ants, which are considered a menace to people, though they can be easily avoided; a column can only travel about 20 metres in an hour. While healthy animals can escape, injured or trapped animals can be killed by the ants which enter the mouths and nostrils of victims. Farmers however have a different relationship with the ants which can clear entire fields of all agricultural pests in an afternoon.