Wow, Deborah, I would go the route Beth went. You absolutely DO NOT want those guys in your roof. It isn't just the damage to the roof, it's other, additional damage they can do.

I had not heard of the stuff Beth ordered.; What I have used to evict unwanted wildlife is ammonia crystals. None of them like that smell. It i extremely effective and quick at getting them out.

Do not consider for a moment leaving them up there.

Your critter ridder guy has a good point that overhanging tree branches will be an invite to unwanted wildlife.