Is the 3 second rule true? Ricky tests dropped food
We've all heard of the 3 second rule - the idea that it's safe to eat food you've dropped on the floor if you pick it up quickly.
Now scientists at Manchester Metropolitan University are trying to discover what happens to food when it's dropped on the floor for a short time.
Some people think that if you drop food and pick it up within 3 seconds and dust off the dirt, then you can munch away without the risk of germs.
Ricky's went to investigate.