Chigger bites? Your grandma may have told you to put clear nail polish on them to keep from itching, the theory being that chiggers burrow deep down in your skin and by sealing off your skin with polish, you suffocate the little mites. But does it really work?

"No and most definitely no," says Ludek Zurek, research entomologist with Kansas State University Research and Extension. "Chiggers can't burrow."

They are actually easy to brush off, he says, especially when taking a warm, soapy shower. So if the nail polish seems to work, it's probably because you brushed them off with the polish.

Unfortunately, you most likely don't realize they are crawling on you until the itching begins, which is usually six to eight hours after they bite. And it doesn't help matters that they are hard to see.

"Chiggers are only 1/150 inch in diameter," says Tom Fowler, with the University of Missouri Extension Service in Buchanan County. "So they are very small."

If you've ever been plagued with masses of itchy bites, you may think the critters compensate for their size with enhanced biting abilities, coming back to feed on you over and over again. But that's another fallacy, Mr. Fowler says. Once they are dislodged, they die, he says.

"They do not live to fight another day."

The reason you can get multiple bites is because chiggers tend to be clumped, Mr. Zurek says.

"Some areas can have whole congregations of chiggers, while equally good areas have almost none. And high- and low-risk areas can be just yards apart."

Our experts agree the best way to avoid chigger bites is to avoid walking or sitting in damp, shady areas with tall grass and weeds. Or when in these areas, wear long pants, tucked into socks, a long-sleeved, buttoned-up shirt and use a repellent containing diethyl-meta-toluamide, or DEET. Afterwards, take a shower and put your clothing immediately into the washer with soap and hot water.

When such efforts are too late, the best treatment for bites is to apply a combination sealant-antihistamine, such as Caladryl, Mr. Zurek says. It contains calamine lotion to control itching and benadryl to serve as a histamine blocker. Then wait for cooler weather. After the first freeze, chiggers are history.

Lifestyles reporter Sylvia Anderson may be reached at sylviaanderson@npgco.com