Scummy hideout.

A scrub-a-dub in the shower makes your body squeaky clean, right? Think again. Researchers have found that shower curtains are home to loads of bacteria that may cause disease.

Scott Kelley, a microbiologist from San Diego State University, and colleagues scraped the soap scum from four shower curtains. When he examined the slime under a microscope, he was shocked. "We found billions of bacterial cells all Over the [microscope] slide," says Kelley.

Harmful buggers? The bacteria's DNA (genetic material) showed that most of the organisms were related to one of two types of opportunistic bacteria. That means they're harmless to healthy people, but dangerous to those with a weakened immune (body's disease-fighting) system.

Kelley says the bacterial guests most likely feast on volatile organic compounds (carbon-containing chemicals that evaporate easily). In other words, they thrive by eating your farts and belches!

Lesson Plans

Learn more about microbes like bacteria with the American Society for Microbiology's mystery game: www.microbe.org/

Check out this CNN article to read more about the shower-curtain bacteria: www.cnn.com/2004/TECH/science/02/15/microbes.everywhere.ap/

Find out how antibiotics work to kill harmful bacteria: http://health.howstuffworks.com/question88.htm