Bumblebees are social insects which generally nest underground, often taking advantage of abandoned mouse burrows. They are fairly large, robust insects about 3/4- 1 inch in length, covered with fine hairs in alternating black and yellow stripes.

Bumblebee colonies contain three castes: queens, drones (males), and workers. Colonies are generally annual with the queens over-wintering and starting new colonies in the spring. Bumblebees are found mainly in northern temperate regions, though there are a few native South American species and New Zealand has some naturalised species that were introduced around 100 years ago to pollinate red clover. They range much further north than honey bees, and colonies can be found on Ellesmere Island in northern Canada, only 880 km from the north pole!

With the recent popularity of using bumblebees in glasshouse pollination they will probably be found in most parts of the world before long (see below), especially Bombus terrestris which seems to be the most popular species sold for this purpose.

These bees, as with other bees and wasps of the Order Hymenoptera, are very beneficial in that they are important pollinators, although less so than the more prolificate honey bee. Unless the colony poses a health risk to humans or pets, it is generally advisable to leave these beneficial insects in peace.