We all know too well how easily things get dirty. Dust gathers, and stains appear, seemingly out of nowhere. That’s no exception for the Animal Kingdom, either. But for some of these critters, staying clean isn’t just a matter of being comfortable. It’s also a matter of survival. The question of how animals manage to stay squeaky clean is something that researchers, including David L. Hu of the Schools of Biological Sciences and Mechanical Engineering, dug into in 2015.