@Armchaircouch - this time of years, milk and cookies?

@Armchaircouch There are "vermin" control services that can remove and exclude the animal. We had a squirrel die in our stove vent system, it was not good. Whether it's stuck or not, you should get it out of there.

@Armchaircouch
County cooperative extension office?

@Armchaircouch
I recommend calling a pro animal removal specialist rather than trying to remove it yourself because of the risk of rabies if it's a raccoon or bats. Your local police department might be able to recommend one.

@Armchaircouch
Probably a bird. We would open the stove doors so it could see light below and go to that. Then we would just open some windows and wait for it to fly out.

@Armchaircouch THat's a lousy situation, I'm afraid. Unless you have a ground level "porthole" to the chimney that could allow access to the critter, or let them find their way out, then I think you'll need to prepare for a few day of foul odor once the poor thing dies.

@Armchaircouch it is most likely a raccoon. Call an exterminator! DWR does not do extrications in my area, unfortunately.

@Armchaircouch Used to get starlings in mine all the time. They'll fly toward anything that looks like outside, so maybe open nearest window. I've managed to corner one and catch it to shoo outside, the others just flew out.

If it's a squirrel I got nothing, except maybe film the situation.