You can try doing your own pest control, but most insects are going to respond better to professional chemicals. On arachnids or spiders, since they do not groom themselves, only certain types of chemicals will work. Bugs are sometimes hiding in the attic or specific crawl spaces, and without the proper equipment to apply and get in these spaces, a person doing it themselves may not be able to eliminate the pests. In fact, you run the risk of forcing the pests and spiders into their hiding spots.