Twenty plus years ago I use to trap flying rats in a downtown area for shoots and retriever training. When it became "public" knowledge I was asked to stop by town officials. Even though is was on a private roof top area they were afraid of the up roar it could cause. I lost a easy source of 500-600 birds a year.
You would think that without trapping the population would have exploded. They are almost completely gone today. Seems the town started feeding the flying rats Decon. Off they went to die in peace and the anti hunters knew that I had been stopped for good. More than one way to skin a cat or kill a flying rat.