hmmm If your gonna go get food for dinner you going to go to a supermarket or wander around an empty football stadium looking for leftover popcorn?
OF COURSE their diet was biased towards aquatic insects because if your a flyer, looking for flying insects, your gonna go where the highest density of food is and where there are the fewest obstructions....i.e. over/near water.
The same thing for ag areas. Their diet is simply reflecting the environment they are in.
Still, since I spent a large amount of time doing much the same thing for deer in college, I'm sure DNA bat poop analysis has to be exciting...to someone
I'm not scared of the dark, it's the things IN the dark that make me nervous. :)