Thanks TJH, the tranny area is what I was going to focus on next, but the AC flap is interesting... could very well be. I'm going to have to pull the dash/ blower fan out to clean it all out again anyway.
EDIT: where exactly are you talking about?
Exterminators had no better answers... just kill em... one by one by one. They just tell me to try to find how they are getting in.... hence my forum plea.