In reply to: Homeowners, what do you hate about owning a home? posted by gregmorrissey
Google: How to keep animals out of the chimney.
You will see a pretty good selection of caps you can place on the top of the chimney.
It would be a good idea to build a fire first to have the animals exit through the top first before you cap the chimney.
But you would want to cap it very soon after the fire in the fireplace, I would imagine.