Good morning and thank you for your question.  At Ohio State, we prefer to use an integrated approach to pest management verses the standard, routine quarterly sprays. It may be a personal preference for some to spray anyway just for peace of mind, even though they may not have a pest problem.  Typically, pest management companies use a broad spectrum insecticide which creates a barrier against all arthropods from entering their structure.  

We strive to use pesticides as a last resort where possible.  But every circumstance may be different.  We can deny arthropods entry by sealing cracks, ensuring door sweeps and screens are in good repair. We can remove debris or food items that may encourage insects where they are not wanted. That being said, an occasional invader may occur from time to time. You may also use a more targeted pesticide again a specific pest.  For example, the use of ant baits and gels which will target only the ant problem at hand, and not disturb other arthropods. 

An exterior perimeter treatment will keep out anything that comes into contact with it, including the occasional invaders (ants, beetles, spiders, isopods, etc.. ) that may wander into your home. Many of these are a mere nuisance and do not warrant management. However, These same insecticides treatments will also kill lady bugs, bees, and other beneficial insects that come into contact with it. 

Here is a factsheet that you may find useful:  https://ohioline.osu.edu/factsheet/anr-68

Please let me know if you have any other questions.