Q. We often get these beetles in our house…at least I think they’re beetles. They’re black and look kind of like a cockroach and they run really fast. I see them outside too, on our front porch. Do you know where they’re coming from?

A. Can’t say for sure without seeing a specimen but I think you might be talking about ground beetles. They do have long antennae and long legs like cockroaches. They’re about the size of cockroaches. They do run fast. And ground beetles are attracted to lights so it makes sense that you are seeing them on your porch. They are probably then getting inside through openings around doors and windows.

Ground beetles come in lots of shapes and sizes, but most are between 1/2-inch and 1-1/2 inches long and are shiny black with ridged wing covers. Some have metallic blue/green or reddish markings. Some can fly. Ground beetles are beneficial insects; both adults and larvae feed on other insects, especially insect larvae. Ground beetles are common next to building foundations where they spend the day hidden in loose soil, or under stones, wood, leaves, or debris. At night they come out to feed on insects. The wormlike larvae spend their time in soil or hidden and are usually not seen.

Adult beetles become a nuisance when they are attracted to outside lights. They then find their way indoors looking for places to hide during the day. They will also enter buildings if outside food sources become scarce or if there are changes in outdoor moisture levels. They usually don’t survive long indoors, they don’t do any damage to household furnishings, and they don’t bite. Some give off a foul odor if handled or threatened.

The best control for ground beetles is prevention: eliminating outdoor hiding places around the foundation like wood and stone piles and heavy mulch; reducing or changing the outdoor lights that attract them; and sealing openings around windows and installing sweeps under doors that let them in. Our trained pest control technicians at Colonial can pest-proof your home to keep ground beetles and other outside pests out. We also offer a semi-annual, outside perimeter treatment that puts a barrier around your home to keep invading insects from getting in. Call us today to schedule your service.

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