The results of a recent study characterizing microbial communities in public restrooms may be enough to change the ways of those who don't already wash their hands after using the toilet. The study found that restrooms are dominated by human-associated bacteria--particularly those from the skin, gut, and urinary tract. Although this is not particularly surprising, the "biogeography" of these species--or which surfaces they were most commonly found inhabiting--was a bit unexpected. While there were three distinct clusters of species (bacteria on or near toilets, those on the floor, and those on surfaces mostly touched by hands), there were also several groups of bacteria that were present on all surfaces. This includes gut and urine bacteria, which were found not only on the seats and handles of toilets, but also on sink faucet handles, soap dispensers, and even on the handles of doors leading out of the restroom--in other words, the areas touched after hand-washing has already been completed.