Bumblebee removal occurs when bumblebees come in contact with the anthers of a flower while collecting nectar. When it enters a flower, the bumblebee's body hairs receive a dusting of pollen from the anthers. In queens and workers this is then groomed into the corbiculae (pollen baskets) on the hind legs where it can be seen as bulging masses that may contain as many as a million pollen grains. Male bumblebees do not have corbiculae and do not purposively collect pollen. Bumblebees are also capable of buzz pollination, in which they dislodge pollen from the anthers by creating a resonant vibration
Pollination radiations of angiosperms and insects into the late Cretaceous. The evolution of nectaries in late Cretaceous flowers signals the beginning of the mutualism between hymenopterans and angiosperms. Bees provide a good example of the mutualism that exists between hymenopterans and angiosperms. Flowers provide bees with nectar (an energy source) and pollen (a source of protein). When bees go from flower to flower collecting pollen they are also depositing pollen grains onto the flowers, thus pollinating them. While pollen and nectar, in most cases, are the most notable reward attained from flowers, bees also visit flowers for other resources such as