While predation by rats is curious news, much more common (here in the US at least) is predation by raccoons.

Conservation-minded management practice is often to build a "bat friendly" gate at the entrance of a significant bat cave or an abandoned mine portal. These gates are the ideal perch for hungry raccoons to pluck bats right out of the air. Bats emerge from entrances like this near the ceiling, when possible, specifically to avoid predators. Poorly designed gates are the opposite of "bat friendly" and turn the safe entrances into buffets for raccoons.

Why do we care about protecting bats? They're the #1 predator for night-flying insects, which are often crop destroying pests. Every bat we lose equals more chemical pesticide that farmers must use to efficiently grow crops.