Bees are flying insects closely related to wasps and ants, known for their role in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea and are presently considered a clade, called Anthophila. All extant bee species belong to this clade; extinct groups include the Paracolponyxini (a basal group) and Mellitosphecinae (controversial placement).
There are nearly 20,000 known species of bees in seven recognized biological families. They occur on every continent except Antarctica, in every habitat on Earth that contains insect-pollinated flowering plants. Some species including bumblebees and carpenter bees are social while others including sweat bees and leafcutter bees are solitary.