Microbiologist Dr. Chuck Gerba doesn't like bagless vacuum cleaners. At least with bags, he says, you can throw away most of the nasty stuff you pick up from the floor. With bagless models, the germs hang on even after you dump the dirt. And that's the good news; the rest is all bad.

When testing vacuum cleaners of all kinds, Dr. Gerba and his intrepid band of germ finders discovered that any vacuum can harbor bacteria like E. coli, mainly by virtue of the bristles, which are constantly in contact with all the gross stuff on the floor – Meals on Wheels for bugs, he says.

There's not much you can do about it, though, so don't go crazy thinking about how dirty your cleaning supplies really are. After all, you can't exactly soak a vacuum cleaner in bleach after each use. Remember what Dr. Chiu says and don't take cleaning to the extreme – your baby's immune system will thank you for it.