Categorize this under both "yuck" and "awesome." A combination which, by the way, means that you're about to give a young science enthusiast the best present -- ever. The Bacteria Growing Kit includes six petri dishes that are a sizable 4 inches (10.1 centimeters) in diameter, a plastic beaker, agar (used to feed the bacteria), cotton swab and an activity guide.
Soon, novice researchers ages 6 and older will realize how much bacteria there is on common surfaces like door knobs, toothbrushes (and even the dog's mouth) as they swab samples to use as experiment fodder. After rubbing the used swabs on the agar contained in the Petri dishes, they can grow a crop of bacteria in about a week. While this kit doesn't include a guide that helps identify bacteria (just think of how many pages that would need to contain!), it does offer a surprising look at the bacteria that exists all around. And could encourage better hand-washing to boot.