Clusters of Tiny Bugs Make Their Annual Spring Appearance on My Window Sills - Ask Extension
I am eager to identify a cluster of tiny black bugs that appear on my window sills at the first sign of Spring. They look dead at first, but soon I w...
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Clusters of Tiny Bugs Make Their Annual Spring Appearance on My Window Sills #621929
Asked April 07, 2020, 1:40 PM EDT
I am eager to identify a cluster of tiny black bugs that appear on my window sills at the first sign of Spring. They look dead at first, but soon I would find myself picking four or five off my curtains, and last season, a couple flew past my TV screen at 2 a.m. while the lights were out. They first appeared about ten years ago and have gotten larger over the seasons (almost 25%). I treat each window sill every couple months with an insecticide to control them until the weather turns cold, then they would disappear until the start of the next Spring season. I have no idea how they get inside because most of the windows remain closed. Some windows sills are worse than others in terms of their numbers. Thanks for your help in finally resolving this mystery!
Prince George's County Maryland
Expert Response
The photo is not clear, but based on behavior and appearance, these are a very common indoor pest called Carpet Beetles (in this case, the Varied Carpet Beetle). More information can be found here: https://extension.umd.edu/hgic/topics/carpet-beetles.
The are drawn to the light of the window in attempts to escape to the outdoors. A thorough cleaning (mostly vacuuming) of out-of-the-way areas and washing any wool or soiled clothing in storage is important to control the population. Blankets that cover a chair or couch, blankets in storage, wool sweaters, and so forth are all textiles that should be cleaned if not laundered in awhile.Given how long this population has been a nuisance, and especially if they are growing in number, it is likely that some area or textile is being overlooked when it comes to sanitation. It is not helpful to spray insecticide for these beetles, and we do not suggest spraying insecticide indoors (particularly prior to an identification) if at all possible.
Miri
The are drawn to the light of the window in attempts to escape to the outdoors. A thorough cleaning (mostly vacuuming) of out-of-the-way areas and washing any wool or soiled clothing in storage is important to control the population. Blankets that cover a chair or couch, blankets in storage, wool sweaters, and so forth are all textiles that should be cleaned if not laundered in awhile.Given how long this population has been a nuisance, and especially if they are growing in number, it is likely that some area or textile is being overlooked when it comes to sanitation. It is not helpful to spray insecticide for these beetles, and we do not suggest spraying insecticide indoors (particularly prior to an identification) if at all possible.
Miri
