I am not one to criticize this game. I have been on it since August and think it is amazing. This game feels like it it is still in its infancy stages and has an unlimited growing capacity. It will only get better over the years to come.
With all of that said, I must say I am not a fan of the bats in creative mode. They become a distraction when I am trying to concentrate on a build. I can live with a sheep, cow or chicken getting in the way once in awhile - they are easily taken care of. Bats on the other hand are fast, random and hard to get rid of.
Hmmmmmm, that reminds me about the wolves when they wrere firstly added in the game. The barks of the dog state were annoying. Too many. With 5 dogs that was a real cacophony. And later Mojang fixed that.
When I read what you wrote, I think that the bats too will eventually be changed, calibrated, etc. It happened for every thing added in Minecraft since I was in, in Alpha state.
I suggest you to analyse carefully the "annoyingness" of the bats the way you see it, and then post it to Mojang.
That makes sense about Halloween Phycozz. I agree, I don't think the bats should go away, they do add something to the game. I'm just not crazy about 10 of them flying around me when I'm trying to do some math on a build.