I believe I mentioned this in another thread, but I prefer to have pest control done by trained, licensed in house personnel.
In the three facilities I have worked in, two did their own pest control, one had a contracted service.
Each state in the US has their own laws and regulations as to who can be licensed. In California and now in Ohio, I am certified and licensed by the state. In Tennessee, the requirements were that you had to work for a "pest control company" for three years before you could be individually certified.
My experience with the contracted pest control companies were less than satisfactory, since I had to fire two of them before I could find a company that would do things the way "I" wanted them done.
The reasons for having pest control done internally (if laws and regulations allow) should be pretty obvious.
1) You are intimately familiar with your facility and it's processes.
2) You are intimately familiar with the condition of your building and grounds.
3) You work there every day and hopefully, are always doing GMP and Pest Control audits, even if you are just walking from your office to the restroom.
If you MUST have an outside contractor perform your pest control, I would strongly suggest you educate yourself as much as you can regarding pests in general, pest proofing, and inspection and control strategies.
YOU schedule when your contractor visits your facility. YOU accompany the service person when he/she does their rounds. YOU point out areas of concern to your service person and ENSURE that the service person thoroughly inspects those areas and treats and/or suggests methods to improve the condition of your building or grounds.
Marshall
I agree with the above but I suppose both methods must be accompanied by people not shrugging off the responsibility. I have an external pest contractor who isn't perfect by any stretch of the imagination, however, they see things occasionally that I have missed on my GMP audits because I am so familiar with my site and audit it regularly which is why I value that fresh pair of eyes.
I've never seen a pest audit which has picked up every pest issue I've found on site though but then that's because I'm fabulous at auditing (modest too

) but I also know that every auditor has their pet hates but also their blind spots.
If you have a wide ranging audit team in a big company then, yes, maybe it's possible but if you're like me and the bulk of the auditing is on your shoulders, fact is you will miss things occasionally, even if you're as great as me!