Foreign grain beetles are tiny and reddish brown. They feed on molds and fungi and are found in many new homes that have not been dried out yet. The beetles do no damage, indeed, they can do good by eating the molds.
Not a Storage Problem
Despite their name, grain beetles do not attack stored grain they eat the mold on the grain. New homes are often built with poorly seasoned timber and, of course, all plaster and mortar is applied wet. Piles of sawdust created while building a new house are often left where they fall into the voids, making ideal bedding and nesting material. Any area that has regular condensation or small leaks in the water system can be attractive to grain beetles as molds will grow there.
Control of the Beetle
If the materials used in the house are dried out, all leaks repaired and proper ventilation of the voids introduced the molds and the beetles will disappear. This is a medium term cure since it will take a couple of years. Regular fumigation with insecticides can give a rapid reduction in numbers but the molds will still exist so the beetles will reappear.
If the beetles are in large numbers they can be swept or vacuumed up and disposed of.