Carpet beetles belong to the family Dermestidae. Their family name comes from the Greek word for skin. Rather an odd name for a family of beetles, you say. But there was a rational reason for its use.
Carpet beetles were employed by taxidermists to clean the soft tissue from their deceased subjects, something the beetles did with exceptional efficiency. Many modern-day taxidermists still use them. They're cheaper and do a better job than the chemicals available. Now, if this was all they did, we wouldn't consider them pests. Unfortunately, they also have an inordinate fondness for woolen fabrics, feathers, silk, fur and other natural fibers. They've even been known to eat cloth that was a mixture of natural and synthetic fibers.
Dermestids are very common. Infestations in our homes often originate in birds' nests where the beetle larvae happily munch away at shed feathers. Once this food source is depleted, they begin looking for another free meal for their children (the grownups feed on pollen). This usually means something inside your house. They can enter through any small opening and sometimes will just casually fly through an open door or window.
As with most pest problems, good housekeeping is the number one thing you can do to prevent them from becoming established. Regular vacuuming can greatly reduce the possibility of an infestation.
If they've already managed to get a foothold in your house, you have to follow a number of steps to get rid of them. To begin with, try to find the source. As mentioned above, this is often old birds' nests. However, it also can be the carcass of a dead rodent or other animal or bird. Something else to take into consideration is old furniture; chairs and such often were stuffed with horsehair. Houses built before World War II commonly have animal hair used by builders to strengthen plaster.
Next, treat all carpets, area rugs and upholstery with an insecticide labeled for use in the home. If you don't want to use a pesticide, try steam cleaning. Just be certain that the fabric can be steam cleaned. Any clothing made of natural animal fibers should be washed or dry cleaned. You can stuff clothing in large zipping plastic bags with the air removed and place them in a freezer for at least 72 hours. However, in cases of heavy, wide-spread infestation, you may want to consult a professional.
Tim Lockley, a specialist in entomology, is retired from a 30-year career as a research scientist for the U.S. Department of Agriculture. For answers to individual questions, please send a stamped, self-addressed envelope to Tim Lockley, c/o Sun Herald, P.O. Box 4567, Biloxi MS 39535.