Cockroaches and "The Bomb"
Something very interesting I came across today... Read on...
You've probably heard the story about cockroaches surviving a nuclear war: we die but they live! This is supposed to make you feel better when you have trouble getting rid of these critters.
So, the real truth: radiologists have found that humans can safely withstand a one-time exposure of 5 rems (A "rem" is the dosage of radiation that will cause a specific, measured amount of injury to human tissue). A lethal dose is 800 rems or more (people are exposed to about 16 rems during their lifetime).
Insect researchers have found that cockroaches can tolerate a much higher dose -- really higher! The lethal dose for the American cockroach is 67,500 rems and for the German cockroach it is between 90,000 and 105,000 rems (yikes!). In truth the amount of radiation that cockroaches can withstand is equivalent to that of a thermonuclear explosion. So, show a little respect the next time your chasing one through the kitchen with a spray can in your hand!
Source - http://www.ipm.iastate.edu/ipm/hortnews/1996/12-13-1996/bomb.html