These little nasty buggers are Leptospira, which cause the disease Leptospirosis. Humans acquire them through breaks in the skin or drinking contaminated fluids, usually the result of an infected animals urine. Want something to be paranoid about? Infected mice often urinate on soda cans; that’s a popular pattern for transmission to humans. These bacteria replicate fast and everywhere they go inside of you they damage the blood vessel walls causing vasculitis and causing you to form clots. This is exceptionally annoying because Leptospira tend to really like your liver, kidneys and central nervous system. You know, important stuff. The blood flow gets cut off from the clots, the tissue dies from lack of oxygen and before you know it you’ve got really bad meningitis, liver failure or renal failure. Luckily things like penicillin, amoxicillin and doxycycline are very effective at killing them.