No matter how clean and tidy you are, you can’t help the fact that as a living being, you emit germs as part of your biological processes. It’s just what it means to be a human. In addition to the bacteria that you naturally produce, you also drag bacteria in from the outside. One study that examined what types of bacteria live on common household surfaces found that Staphylococcus aureus (Staph), yeast, mold, salmonella, escherichia coli, (E. coli) and fecal matter might all be living in your home. It’s no reflection of cleanliness habits – even those who live as if they’re in a plastic bubble will still find these germs in their homes. Think about it: you eat and groom yourself and sleep and drool in your home. You use the toilet. Germs are bound to happen.