One key thing you need to consider is the chemicals that the expert will be using. Some states have banned particular chemicals due to their effects and potential danger they pose to people. Some people prefer more natural ways of dealing with pests. If your problem is one which can be dealt with in a more humane way, be sure to ask your professional pest control in Gilbert AZ what they offer.
Some companies will offer new treatments and methods of dealing with pests which don’t involve a huge amount of chemicals which will remain in your home for a prolonged period of time. Perhaps the professional can offer a less evasive chemical option, if there is not a totally natural option open to you. Regardless of what you prefer, is always worth exploring other options, no one wants their home to be packed full of dangerous chemicals unless it is a total necessity, especially if you have children or pets.
Now you have identified the professional you want to use, the methods of dealing with the pest they will adopt and the price they will charge (along with any damage repair they can do on your behalf) the final thing you need to check is their grantee. Because you are dealing with an animal/creature there is no 100% grantee it will be gone on the first attempt. Make sure you find out what guarantees your professional offers in case the creature comes back or is not removed totally the first time. Best of luck in your search.