Pupation occurs in loosely constructed pupal cells within the food source. Adults of both species can fly. Check all old packages of stored foods listed above and discard any food products that you find infested. Pet foods are common sources of infestation. If your home has been previously infested with a mouse or rat, look for old rodent nests.
Rodents often hoard food, such as seed or dog food, in their nests.
Food in such nests can then become the source of a difficult to locate infestation, after the rodents have been controlled. Heat treatment is routinely employed in museums when receiving new herbarium specimens. Heating specimens to 125 F for two to four hours, or freezing infested materials at 0 F for six days, is generally sufficient to kill all life stages. Small quantities of pet food may be disinfested by placing in a cold freezer for two weeks. Pet food treated in this manner can then be safely fed to pets.