Most bumble bees are large, social bees that produce annual colonies. Mated queens overwinter in the soil and emerge from hibernation in early spring when they feed on spring flowers and search for a suitable location, such as a former rodent burrow in the soil, to begin their colonies. These are beneficial insects that pollinate many native and ornamental plants. They can sting severely, so problem nests near human dwellings should be removed by experienced pest control operators.
Bumble bees are easily recognized by the corbicula (pollen basket) on the hind tibiae in the females. Honey bees are the only other bees in Florida with this structure, but are easily recognized by their smaller size, hairy eyes, and lack of hind tibial spurs. Large carpenter bees are often misidentified as bumble bees, but these are readily distinguished from bumble bees primarily due to the absence of pubescence on the dorsum of the carpenter bee abdomen, which is somewhat shiny.
The five species of bumble bees found in Florida are usually separated by the pattern of the black and yellow pubescence.
A number of non-social Bombus species lost their social behavior and the ability to collect pollen, and are now cleptoparasites on colonies of pollen-collecting Bombus species. These cleptoparasitic species were previously listed as being in the genus Psithyrus (ITIS 2011), and are now sometimes listed as a sub-genus. The parasitic species are easily distinguished by the lack of the corbicula. The most common of this group found in Florida is B. variabilis.