Is a bat vermin?

Answer:
That calls for a value judgement. A definition of "vermin" is: Various small animals or insects, such as rats or cockroaches, that are destructive, annoying, or injurious to health.

If they annoy you then they are. They can carry rabies so that makes them injurious to health.

In the broad view, they eat several times their weight in mosquitos (that carry disease) a night and they even pollinate some flowers.

It's your call.

First answer by TargetDriver. Last edit by TargetDriver. Contributor trust: 264 [recommend contributor recommended]. Question popularity: 1 [recommend question].