Thanks for all the information and help. I got up there this morning when it was about 40 degrees to look down the chimney. There were about a dozen cruising up and down the warm air but none coming close to the top opening. I couldn't see any nest or crowd around what would be an entrance to a nest.

I was able to contact a pest service later and they will be out Monday to treat the area with stuff that will kill them. I acts slow enough it should be transported back to the nest and take care of that too. They have a guarantee it will work or they redo it.

So thanks again for the responses.
Steve A.