BOISE, Idaho (AP) — An invasive insect commonly found in south-central Europe has been detected in southwestern Idaho, marking the first time the elm seed bug has been spotted in the U.S., according to federal officials.

A U.S. Agriculture Department specialist has confirmed the discovery of the pests that officials say don’t pose a threat to trees, despite their name — but do tend to enter houses and buildings in huge swarms.

The Idaho Department of Agriculture issued a statement Wednesday warning that the bugs recently found in Ada and Canyon counties can prove to be a “significant nuisance” for homeowners. Elm seed bugs invade homes during the summer to escape heat, and then stick around through the winter, the department said.