The doorknob harbors more germs that are likely to make you sick. But bear this in mind: The vast majority of germs are either harmless or good for you. Naturally, we tend to focus on the tiny minority that can actually do harm, says Jessica Snyder Sachs, author of Good Germs, Bad Germs. “Imagine the floor of a subway train. I mean, a mother would be absolutely grossed out. But, to be honest, unless people are spitting on the floor, the floor may be full of germs, but they aren’t going to get [people] sick,” Sachs says. In contrast, a doorknob harbors mircrobes that you are likely to touch and transfer to your nose and mouth, common gateways for germs to enter the body and make you sick.