These bats are fun to have around and the higher level ones really destroy monsters. As I was playing around with it though, I found a little bug. When I moved to far away from the bat to the point it teleported into my inventory, two would appear. One I could throw out fine, and one with half a durability bar that I couldn't, both named the same. I could give those ones pumpkin pie in the crafting grid and have a working duplicate bat. Makes it pretty easy to amass a whole colony of them.
Other than that it's a great mod, and perfectly on time for Halloween!