That all depends on what type of pest you have, where you are located (as some methods are governed by law) and what is the company's common practice. Some jump straight to pesticides while others...
They hide under rocks so penetration is the key. Either a powers spray, using a hose end sprayer to saturate those areas or a granular that will dissolve over time is recommended.I used to tell...
"Pest offense controls lots of different little bugs and small rodents that invade your home. Some insects may include ants,crickets or spiders. It can also work for things like mice and rats."