You've dropped your sandwich, drumstick, lollypop or Twinkie on the floor. But don't worry. If you pick it up within five seconds, it'll still be safe to eat. Right?
That's the Five-Second Rule. Or maybe you've heard it as the Ten-Second Rule or, in some more permissive and less mysophobic (germ-fearing) societies, "Whatever!"
According to the rule, here's what happens when you drop your food:
The instant the food hits the floor, it becomes a feast for all the floor germs. To them it is manna from microbe heaven -- free food, and the occasion for a big microbe party. The first scout germ that finds the food calls out an invitation to its invidious relatives all over floor: "Come and get it, guys!"
Bacteria swarm to the site from all directions and climb or jump onto what to them appears to be Manna Mountain. After a while, the food is swarming with bacteria and unfit for human consumption. One must snatch it back before the germs have had enough time to envelop it completely.