Grab five slices of bread do the following before putting them in separate bags: 1) put one straight into the bag untouched, 2) let kids touch one slice with dirty hands, 3) have your children wash their hands with soap and water before touching the bread, 4) have them touch a slice after using hand sanitizer, and 5) rub one piece on a frequently used surface of your home. Leave the bread out for a few days and watch the mold spores grow.