Bees (Apoidea Superfamily) are flying insects, closely related to wasps and ants. They are adapted for feeding on nectar, and play an important role in pollinating flowering plants, and are called pollinators. Bees have a long tongue that they use in order to obtain the nectar from flowers. Bees have antennae made up of thirteen segments in males and twelve in females. They have two pairs of wings the back pair being the smaller of the two. Their legs are modified so that they can gather pollen and the apex of their abdomens are modified into a stinger. There are over 16,000 described species, and possibly around 30,000 species in total. Bees may be solitary, or may live in various sorts of communities. The most advanced of these are eusocial colonies, found among the honeybees and stingless bees. Sociality is believed to have evolved separately in different groups of bees.