Windows, doorways, and ventilation openings should be screened with standard window screen material. Preferably such screening should be on the exterior of the building to avoid a cleaning problem from flour dust. Also, the screening of windows that may be opened should be removable to permit cleaning of the glass area. Operational doorways should be kept closed except when in use. Chemicals to control pests should be used, if necessary, only when the exterior of the building has been improved to discourage entry by pests.
Chemicals are at times the best, but only a temporary control measure.
When chemical control is found to be necessary, care should be exercised in what chemicals are used, the amount used. Avoiding contamination of the grain, process equipment, utensils, packaging materials, and the flour and meal products is a must. Pesticides should be used according to label instruction. Unless someone at the grist mill is specially trained in pest control and particularly knowledgeable of pesticides, it is suggested that chemical controls be purchased from a commercial pest control service or operator. If chemical pesticides are stored in the mill they should be stored in appropriate containers away from areas of grain and product storage.