Your belly button is a scar, your very first one. It forms when a doctor snips your umbilical cord, and, depending on how it heals, you could have an outie or, more likely, an innie. And innies are ripe for colonization, not only by lint, hair, and dead skin cells, but also by bacteria.

In one study, 60 volunteers swabbed their belly buttons. Researchers then analyzed the samples and found more than 2,300 kinds of bacteria. That's an average of 67 different kinds per belly button. Now, many of those microbes aren't unique to belly buttons, like staphylococcus, which can lead to staph infections. It shows up in noses, throats, hair, and, yes, even belly buttons.

But the researchers also discovered other bacteria never before seen on human skin, like marimonas, which scientists had previously only seen in the ocean. And they even found bacteria that chefs use to make cheese, and, yes, somebody did exactly that. She grew the belly-button bacteria in a petri dish and then added it to milk. Sure enough, after a few hours, the milk curdled into cheese. Belly-button Brie, anyone?

Use the interactive charts below to explore the dataset