Vermin refers to various small animals or insects, such as rats or cockroaches, that are destructive, annoying, or injurious to health. In general, I do not see where bats fit into that category.
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...
Vermin means animals that are destructive and/or a nuisance to humans. Bats tend not to get particularly noticed by humans at all, so that label don't fit too well. But I guess they could be...
Wooden bats have variance in density and grain direction that might affect the course of the ball as well as an overall lower density that would deform more on impact, however, the difference between...