I've learnt the hard way, like a lot have. But, if you get any calls, always try and establish by careful interrogation, what the nest or bees actually look like. About 5 or 6 times a year i get a call saying" there is bees in my chimney". i ask how long they have been there and they say, since last summer. Be prepared to walk because you get a lot like this. Its a waste of your time to go and see the job, that isn't a job.
I always try and convince the caller their better off in there chimney and not to get them destroyed. if their not in a used chimney, then their usually ok anyway and wont cause a problem.
Ive been to many Bumble bee nest calls and i have relocated 1 nest as it was within easy access and i moved it away to a small garden shed i had. they seemed to do fine. however, most aren't accessible.
Like Pargyle says, tell them they will be gone by august, if their kind creature minded people it wont be a problem.There will be a nest, often it starts off as the remains of a small mamals nest, like rats or mice. but when their finished for the season thee is nothing left unlike a dead out for a Honey bees nest.
I used go to any kind of calls, but now i have a few questions I ask and usually theres not a lot i can do. However i always spend a little time trying to find out exactly what they have. it will save you hours and wasted trips. People in general just dont have a clue and its mostly just a matter of good communication.