Fall Browns are destroying my flies ... It seems that they grind them between their teeth and just shred them. After a dozen or two they're toast, dries or nymphs. Today I caught one nice one- zoom, to the top of the pool, a couple nice aerials, back to the middle under a log, got him out, more aerials, down to the next pool... finally netted him..he opened his mouth and the nymph fell out. It appeared that he just had it clenched between his teeth, he was not hooked.. and of course it was coming apart. It's pretty entertaining..