The cave bats are cool, but having bats that live on the surface or in open caves that are active at night/sunset would be nice and add some (good) life to the night sky (fuck phantoms). There are real benefits to bats; they help with agriculture by eating pests and spreading pollen for many plants, such as mangos and bananas.

They could serve as an alternative to bees that spawn where bee hives don't (they only spawn in forests) and would lack the aggression that bees have, with the downside being that they're only active at night. Outside of that, they would function very similarly to bees in terms of storage & farming, bat houses already exist and store loads of them. Realistically, it wouldn't be that hard to make this into the game.