upstairs bathtub. The apartment had been vacant for a while and the electricity was off because we were doing electrical work, so I couldn't see very well. I grabbed a shovel and slid it under the mouse to carry it to the dumpster and I found out 2 things:
1. It was not dead.
2. The large mouse was actually a large bat. I first realized this when suddenly it made a very loud and unearthly hissing sound and at the same time extended it's wings, which spanned the entire width of the bathtub.
I dropped the shovel and made like a tree.