An Arlington, MA customer found a rove beetle inside. The photos are below, note the serrated antennae. Rove beetles feed on fungus, other insect larva, decomposing organic matter. They normally are not a structural pest, but if an area is extremely wet and a food source exists, insects that are usually outside will be found inside. The solution for this issue is site sanitation, vacuuming the areas inside the beetles are seen, making sure a dehumidifier is used in season and the roofing systems (gutters, flashing, downspouts) are all moving water away from the structure. Around the foundation minimize decomposing organic matter like leaf piles. For more information on this beetle family, follow this link to University of Florida Entomology page on the rove beetle.
-Lauren Greenhow, General Manager, GreenHow, Inc. GreenHow.com. Effective Organic and Low Impact Solutions, Lawn Care, Pest Control and Termite Control in Newton and Metro Boston.