Relationship with humans
Ants perform many ecological roles that are beneficial to humans, including the suppression of pest populations and aeration of the soil. The use of weaver ants in citrus cultivation in southern China is considered one of the oldest known applications of biological control. On the other hand, ants can become nuisances when they invade buildings, or cause economic losses.
In some parts of the world (mainly Africa and South America), large ants, especially army ants, are used assurgical sutures. The wound is pressed together and ants are applied along it. The ant seizes the edges of the wound in its mandibles and locks in place. The body is then cut off and the head and mandibles remain in place to close the wound.
Some ants of the family Ponerinae have toxic venom and are of medical importance. The species includeParaponera clavata (Tocandira) and Dinoponera spp. (false Tocandiras) of South America and the Myrmeciaants of Australia.
In South Africa, ants are used to help harvest rooibos (Aspalathus linearis), which are small seeds used to make a herbal tea. The plant disperses its seeds widely, making manual collection difficult. Black ants collect and store these and other seeds in their nest, where humans can gather them en masse. Up to half a pound (200 g) of seeds can be collected from one ant-heap.