Hi Steve!
This is a tough problem! The best way we have found to stop them from entering your home is to go along each perlin with fiberglass insulation and stuff it between the roof boards and the perlin the entire length. Then, if possible, caulk on top of that.
We use flat putty knives and small round sticks to push this material in. It’s time consuming, but worth the effort if done properly!
Thanks,
The Log Doctor.