Anyone know what they feed on, in general, and what flies would work on
them? I found a great (stocked) pond about 5 km from me, and they were
making huge swirlies all over, especially in the muddy channel between two
ponds.

I waded through a swamp up to a muddy bank (ignoring the malarial
mosquitoes and what ever creepy crawlies were in there) rigged up, and after
the mandatory half hour getting the tippet unsnarled from the waist-high
reeds, out of the trees behind me, and untying Gordian wind knots, I
actually got a chance to see how bad my casts have gotten since this summer.
Then a hellacious thunderstorm rolled in and I had to get out before the
road turned to mud. I actually only 'fished' in any proper sense for about 5
minutes, but I'm dying to get back there, once I get some clues as to what
they will take.

--riverman