September means back to school, the return of cooler weather and the invasion of over-wintering pests. Over-wintering pests are those pesky creatures that move into structures in the fall, camp out and lay dormant all winter, and then emerge with abandon at the first sign of warm weather. The most common over-wintering pests in the upper Midwest include Asian lady beetles, box elder bugs and cluster flies.

Pest control companies receive an influx of calls in the spring when these pests try to exit homes or businesses. The best way to avoid seeing them in the spring though, is to prevent them from entering your home or business in the fall. So, how do you keep over-wintering pests out?