This beetle looks similar to many of the stored product beetles, but unlike the food pests, the foreign grain beetle can fly. These beetles are a fungus and mold feeding species that can squeeze through screens and vent openings. Insecticides are not very effective. Keep select windows closed during the day, and dry the structure out using dehumidifiers or heating will help. The problem will stop after the first hard freeze.
Nymphs are bright red.
On sunny fall days in late summer and fall hundreds may cluster on sides of buildings and begin moving into sheltered areas to overwinter. During the winter insects from wall voids and attics may migrate into the living space and create a nuisance. Since breeding goes on only on boxelder and silver maple trees during the summer, one solution is to remove the tree for control. Insect proofing should be the second option. If barrier treatments are used they need to be applied before the insects get into wall voids.