Stored product pests (SPP) are almost as varied as the materials they contaminate: rice weevils, grain moths, Indianmeal moths, flour beetles, cigarette beetles, drugstore beetles, and saw-toothed grain beetles, just to name a few.
Simply controlling the visible insects will not eliminate the problem. You have to root them out at the source.
Chances are good the infestation probably began in open, partly used bags or boxes of foodstuffs left in the backs of food shelves, pantries and other food storage areas. And you will have to be thorough and exhaustive in your search. Most SPP, most of the time, will go further in their foraging efforts.
That means extending your search and tracking down other, less-obvious food sources, such as bird feeders, door wreaths and dried flower arrangements, house plants and pet food bowls.
Whatever method you use to control SPP, you also should carefully vacuum all the infested shelves and clean out every crack and crevice you can find.
Last but certainly not least, explain to clients that sound sanitation and sealed storage containers will help prevent future infestations. Transferring food products to sealable glass or plastic containers is a good place to start.