Have you ever had a relative or someone else that you just didn’t care that much for, and you’d rather they didn’t come to stay at your house? Maybe you try to make things so that person doesn’t want to come over — you’re nice, but the person feels uninvited. This approach might not work with relatives, but it certainly can with pests.
It starts by understanding what motivates pests. Like people and all other animals, pests respond to food, water, shelter and temperature. They typically have such short life spans that each pest works hard to find the things it needs to survive. If your facility has plenty of what a particular pest needs, it is bound to gravitate to those sites in and around your building. The way you uninvite pests is to identify those factors or conditions that are attractive to pests and then eliminate or minimize them.
Temperature is critical to cold-blooded creatures like insects and spiders, less so for rodents and birds. We keep the inside of our buildings at a comfortable 68° to 75°F which is just fine for most insects. During summer, it might be the cool air currents exiting cracks around doors and windows that attract flies; during fall it is the warmer air currents and the warmth of walls that attract many pests. Insects live in a microclimate world and once on a building, they will seek out the temperatures most suitable for them. If you have openings or cracks in the outside walls and around doorways and windows, insects will find these and come inside.
Simply sealing as many cracks, gaps, and other openings as you can and ensuring tight-fitting screens over vents and windows goes along way toward excluding pests from gaining access inside.