I have a couple of thistle socks hanging on the front porch for the finches, but after taking some photos which didn't turn out good (window glare and too much backlighting from sun), I noticed the birds on them were not finches. That day there was a huge flock of them which is why I took photos since there hadn't been any on them for over a week. When I downloaded I knew it wasn't a goldfinch ... nor the yellow-rumped warblers which I'd seen just arrive who were enjoying the suet feeder. So what are they? Some other kind of warbler that's late passing through Central Piedmont Virginia?