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.
White blood cells help the body fight against infection. There are many different types of white blood cells, which include: 1  Lymphocytes, neutrophils, and monocytes. 2  These white blood cells fight against invading bacteria, viruses, or fungi to help destroy infection.nside the marrow, blood cells start off as young, immature cells called stem cells. Once they develop, blood cells do not live for a long time inside our bodies. This is why our marrow continuously produces all three types of blood cells to keep us healthy.