quality:corruption
Feeding

The bumblebee tongue (the proboscis) is a long, hairy structure that extends from a sheath-like modified maxilla. The primary action of the tongue is lapping, that is, repeated dipping of the tongue into liquid. The tip of the tongue probably acts as a suction cup and during lapping, nectar may be drawn up the proboscis by capillary action. When at rest or flying, the proboscis is kept folded under the head. The longer the tongue, the deeper the bumblebee can probe into a flower and bees probably learn from experience which flower source is best-suited to their tongue length. Bees with shorter proboscides, like Bombus bifarius, have a more difficult time foraging nectar relative to other bumblebees with longer proboscides; to overcome this disadvantage, B. bifarius workers were observed to lick the back of spurs on the nectar duct, which resulted in a small reward.