No matter how often you hit your home with a bottle of Lysol or a container of Clorox, it’s still likely teeming with germs. In fact, when researchers at the University of Colorado at Boulder collected dust samples from 1,200 American households, they were able to identify more than 9,000 different species of microbes, bacteria, and fungi. Put simply, there’s a huge amount of germs hidden on your doorknobs and under your couch cushions.
Though the best course of action would be to do a deep clean of your house every week, it’s admittedly unrealistic to devote so much time just to get things spick and span. That’s why we’ve compiled a list of the dirtiest things in your home that you can—and should—focus on the next time you break out the disinfectant.