I can see plenty of pest-specific topics on here, including an at-home solution. However, my question relates to general pest control, and when to know to call in the big guns.
I maintain rental properties which currently have a pest control schedule. Due to pricing discounts, I also group my own home into this as well. None of the homes seem to have a real infestation issue; all are mostly preventative.
Are the chemicals used in most pest control available over the counter? Are there any good resources for mixing your own? The only resources I know of is big box home stores, and their options can seem limiting at times (Or at least brand-name expensive).
If I were to start to do this for the majority of pest control options; I'd save a lot of money, but was unsure if chemical potency could be matched.