Control of flour beetles requires locating and eliminating infested items. All potentially infested foods should be checked. Look for tiny holes where they have chewed through the packaging of flour or other dry cereal products that are stored in your kitchen or pantry areas. The insects may be in unopened boxes or containers. Infested items can be thrown away. Empty and thoroughly vacuum clean cupboards including the cracks and corners. Vacuum cleaning picks up hiding insects and spilled or infested material. Empty the vacuum cleaner or discard the vacuum cleaner bag after use to prevent reinfestation. The flour beetle may crawl or fly to the other areas of your house.

https://extension.umn.edu/product-and-houseplant-pests/pantry-pests-insects-found-stored-food

These insects enter your house in infested milled cereal products. Check all packages of flour, noodles, cereal, macaroni, or cake mix and even dog/cat food and birdseed for beetles and larvae (small, white grubs). Finding the source of an infestation is not always easy. Infested packages are usually the oldest, most difficult to reach foods in the pantry. Even unopened containers may be infested; some pests can easily penetrate plastic, waxed paper, and cardboard containers. Before buying an item in the store, check that the bag or container is well sealed and undamaged. The most commonly infested pantry items are birdseed and dog and cat foods. Store pet foods in well-sealed plastic buckets or storage containers and use them promptly. Transfer all products containing milled cereal grains to tight canisters, glass jars, or sealed plastic containers to store products.