Bumblebees are social insects that are characterised by black and yellow body hairs, often in bands. However, some species have orange or red on their bodies, or may be entirely black. Another obvious (but not unique) characteristic is the soft nature of the hair (long, branched setae), called pile, that covers their entire body, making them appear and feel fuzzy. They are best distinguished from similarly large, fuzzy bees by the form of the female hind leg, which is modified to form a corbicula: a shiny concave surface that is bare, but surrounded by a fringe of hairs used to transport pollen (in similar bees, the hind leg is completely hairy, and pollen grains are wedged into the hairs for transport).
Like their relatives the honey bees, bumblebees feed on nectar and gather pollen to feed their young.
The Hymenoptera are one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. Over 130,000 species are recognized, with many more remaining to be described. The name refers to the wings of the insects, and is derived from the Ancient Greekὑμήν (hymen): membrane and πτερόν (pteron): wing. The hind wings are connected to the fore wings by a series of hooks called hamuli.
Females typically have a special ovipositor for inserting eggs into hosts or otherwise inaccessible places. The ovipositor is often modified into a stinger. The young develop through complete metamorphosis — that is, they have a worm-like larval stage and an inactive pupal stage before they mature (See holometabolism).