You now have to farm cows to get leather to make books which turn makes bookshelves for your enchanting rooms. So I realized that the Bats were pretty useless, So I decided that lore-wise its not too far of a stretch to allow Bats to drop leather when their killed. Thus this mod was born. They also have a chance to drop a melon seed when killed, so be on the lookout! They also drop Experience Orbs now!