Not vampire bats, I trust. Just LBBs (little brown bats).
The bats were harmless enough clinging to the walls of the arena. They do eat insects and other creepy crawlies, which is a good thing. They left the horses alone and the horses didn't seem to notice them. However, the sonic squeaks did give Genevieve a headache. My aging hearing system only picked on the high-pitched squeaks when I was close to the bats -- but I could see how it would make one do the "doggy head shake" (What the heck was that?!).
So, given the presence of bats, do I change my assessment of Twilight? Hmmm. I think I'll wait until the LBBs become more ominous.
I won't cry "Uncle" just yet.