Very, very nice and funny idea, really creative... And I wonder how much it's "economically" worth the effort. Again: This is the stuff I like this community for, I'm happy to be shown this! I'm asking for information.
How many bats did this contraption farm? I can't read the numbers. I always dealed with these pesky swarms with bomb arrows (one has to be quick with them as the swarms start to evade you as soon as you take out your bow), and I often got ten or more bats out of one (quick) shot.