If you wanna give it a shot yourself and save a little bit of money, you're going to need to buy a product called Phantom. The awesome thing about this chemical is that insects cannot detect it so they will eventually expose the harmful chemical to other insects and kill them. Exposure occurs by contact, grooming and food exchange.
My dad owns a very successful pest control company and we use Phantom 99% of the time, it's a very good product that works.
Link:
http://www.domyownpestcontrol.com/ph...ide-p-209.html