You've likely heard of the "five-second rule." Some even stretch it to 10 seconds. But is there any truth to it? Is food really still safe to eat if you drop it on the floor and pick it up within that time frame?

The short answer is yes, but also no.

Tom Melendy is an associate professor of microbiology, immunology and biochemistry at the University at Buffalo. He says it all depends on what falls and where.

Food or whatever you drop is like a sticker. If there is stuff on the ground, it sticks to that item. Bacteria don’t move. If it’s a wet or sticky item, it will pick up more of whatever is on the floor. Obviously, if the floor is cleaner, you’re better off.

In terms of timing, it all depends on what was dropped. A chip will pick up less bacteria than a sticky gummy.

Melendy says it takes a lot of bacteria to get you sick.

“So, it is a numbers game," Melendy said. "Remember that children have been eating dirt probably since the dawn of human history. It's something they do. The element of taste is part of their exploring the world, and they usually get over it after a short time.”

As for cleaning, Melendy says white vinegar is always a good option and it's a safe, chemical-free floor cleaner in case your child might some day eat something off the floor.