Bumblebees of the subgenus Psithyrus (known as 'cuckoo bumblebees', and formerly considered a separate genus) are brood parasites, sometimes called kleptoparasites, in the colonies of other bumblebees, and have lost the ability to collect pollen.ueen and worker bumblebees can sting. Unlike in honeybees, a bumblebee's stinger lacks barbs, so the bee can sting repeatedly without injuring itself; by the same token, the stinger is not left in the wound. Bumblebee species are not normally aggressive, but may sting in defence of their nest, or if harmed.
STEM CELLS SAVE LIVES. For decades, doctors have harnessed the unique ability of stem cells to treat leukemia and genetic blood diseases. But now, researchers are discovering that these cells have the power to heal, to fight disease, and to regenerate damaged or aging tissue throughout the body. To fully understand why they hold the potential to change your childâs medical future, get to know more about stem cells.
-They have a high rejection rate-It is difficult to tell how the stem cells will 'take' (in one experiement, they placed the cells in a woman's brain stem, and they formed a tumor that grew flesh, bone and hair ON HER BRAIN that grew and killed her!) In short, there are a lot more advantages to using adult stem cells.