There was a live bat in our room. And no, it did not come in later: the window was closed, so the animal was already there when we were given the room.
We went down to reception to ask for help, and the first reaction was to suggest that we solve it ourselves. When we refused, they sent a worker who checked the bathroom, said that we were probably mistaken, and left. Evidently, the bat was still there. In fact, I ended up finding it myself.
Finally, he returned and tried to scare it away with a broom and a towel to get it out the window. He succeeded, but during that process, my earrings were broken.
Afterward, we requested to change rooms because obviously, we were not going to sleep there. They told us that the hotel was fully booked. After insisting quite a bit, they moved us to a lower category room, which we accepted only because our priority was not to stay in the room where the bat had appeared.
That new room was assigned to another guest who had not yet arrived (it was already 10:30-11:00 PM), so they quickly cleaned our room to give it to that person.
I completely understand that finding a bat in a room is not something usual and that the staff probably do not face situations like this every day. The disappointing aspect was the management: minimizing the problem, suggesting that we resolve it ourselves, and not offering any type of compensation for the inconveniences, the material damages, or for ending up in a room inferior to the one reserved.