Should you take off your shoes in the house? Scientists weigh in.

Mark Patrick Taylor is Chief Environmental Scientist, EPA Victoria, and Honorary Professor, Macquarie University. Gabriel Filippelli is Chancellor's Professor of Earth Sciences and Executive Director, Indiana University Environmental Resilience Institute, IUPUI.

You probably clean your shoes if you step in something muddy or disgusting (please pick up after your dog!). But when you get home, do you always de-shoe at the door?