Bats in the bathroom

Being more organised than usual, I had shut the big door before getting into the bath. Had a vague idea that I might read in the bath and would need the light on and then all the bugs would make a bee line for me.

But just for now it was just light enough to see but not light enough to see the wobbly bits in the bath! As dusk fell there were a couple of bats flying outside the window, highlighted against the sky and I was smugly thinking that they were safe outside. Vaguely wondering how they were managing to make the shadows across the ceiling with the light falling as it was. With my usual speedy thought process...... oh my God it's in here.

Him Outdoors fortunately was within screech shot and opened the doors to let the poor thing escape - not the others in!

Now does the bat spend the day in the barn and had got shut in, or had I shut it in after it had come investigating at dusk?? Surely if it lived in the barn you would see some crap or something, but then it must have some clever mechanism for crapping whilst hanging upside down or it would crap on its head. David Attenborough has to climb over mountains of crap to get to a bat cave, so how do they do that?