This datapack is based on the idea presented in Ethoslab's Let's Play episode #590:
"Bats should drop Echo Shards"
You can find a collection of the EthoMIX (Etho Minecraft Ideas eXplored) databacks here.
This addition helps players early in the game to get a useful item (recovery compass) that would normally require going to one of the most dangerous areas in the game, and also gives bats a purpose other than ambience.
The Bat Droppings Team
