Carpet Beetles are Welcome in my House if it Means not Having Bed Bugs!

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By Marcia Anderson

Several months ago I received an e-mail from a city resident who was getting bites at night that she thought were from a spider. Large, and itchy, but with a burning sensation that told her they weren’t mosquito bites. The problem escalated until she had over 40 red welts on her legs. “I was getting groups of about 5-20 ‘bites’ every night, and my husband had none, and he wore boxers! Also, after the first few nights, I was wearing heavy sweat pants to bed tucked into my socks, and still found marks! “

Carpet beetles are cariophites, which means they live on dead organic materials

She cleaned and vacuumed everything in the bedroom and changed the sheets, but the next morning she still had a few bites. She then went on the internet, and found that this was NOT the work of a spider, but possibly bed bugs. They quarantined the bedroom after thoroughly cleaning and spraying everything with over-the-counter pesticides, but no evidence of ANY bugs was found. She checked the sheets for blood spots, actual bugs – dead or alive, and shed skins, but found none.

One pest company had given her a quote of $1200 to come and treat for bed bugs, but a second pest company suspected carpet beetles instead of bed bugs due to the fact that the wife was getting the ‘bites’ and the husband was not. Some people are allergic to carpet beetles and some are not, however, almost everyone has some allergy to bed bugs. The pest company arrived, and upon inspection, no bed bugs were found, however, a few dead carpet beetles were discovered.

Just like bed bugs: 1.) carpet beetles are attracted to you when you are sleeping because of the CO2 gas you exhale, 2.) carpet beetles are very shy, so they are hard to find, and 3.) carpet beetles also usually come out in the wee hours of the morning. The difference is: bed bugs bite, but carpet beetles eat natural fibers, like wool blankets, natural fibers and feathers, and do not bite.

An adult bed bug next to a carpet beetle larvae.

She learned that they did not need to chemically treat for carpet beetles, as it isn’t the live insects that cause the allergy. Carpet beetle larvae have prickly little hairs that cause a reaction in some people that looks very much like bed bug bites. The solution is to make sure all the allergens (the hairs) are removed from the environment. People with sensitivity to the hairs may get some relief by not wearing shoes or socks in the house. A build-up of static electricity can cause the micro fine hairs on the larvae to impale themselves in human skin, thus creating a small pin-prick-like wound. The ‘bite reaction’ under clothes is symptomatic of carpet beetles, as the hairs can pass though all but the finest of weaves on clothes.

The treatment: she had her carpets steam cleaned.

The moral to this story is: if you search for bed bug signs and find no traces, carpet beetles could be the pest, especially if you are getting a number of bites every night. Check the area (with a magnifying glass) for the shed larval skins remembering that even a single carpet beetle skin could result in multiple “bite like” reactions due to the number of hairs they carry.

About the Author: Marcia is the bed bug and vector management specialist for the Pesticides Program in Edison. She has a BS in Biology from Monmouth, second degree in Environmental Design-Landscape Architecture from Rutgers, Masters in Instruction and Curriculum from Kean, and is a PhD in Environmental Management candidate from Montclair – specializing in Integrated Pest Management and Environmental Communications. Prior to EPA, and concurrently, she has been a professor of Earth and Environmental Studies, Geology and Oceanography at Kean University for 14 years.