This scary looking creature from the family of bacteriophages, or phages for short. Discovered independently by Frederick Twort in 1915 and Félix d’Herelle in 1917, phages were used to treat cholera by scientists who did not yet know how they worked. In 1940 was the first time phages were seen under an electron microscope and scientists realized how they work. This virus infects bacteria and cannot survive or reproduce without it. Once they invade a host cell they can consume the host's nutrients and reproduce.