They're out there. Creatures you can't see. Creatures you can't hear. They're creatures that live off our flesh. They thrive in dark corners, in places you'd never expect. They found a place to live on your doorstep, in your kitchen, under your bed. Wait a minute guys. This isn't so scary. Many of the species in your house, in your bedroom, on your body, even under your bed are good for you. We have scary things living around us lots and lots of beneficial ones. What we want to learn is where those different kinds of species are. And how the way that you live is influencing those species.