There was an absolutely furious yammering going on out on the deck--it sounds like somebody running a gravel-filled squirrel backwards through a rusty wood chipper. I finally got up to see what it was, and discovered a juvenile pine warbler clinging to the tree next to the suet bar, screaming/chattering its head off. A woodpecker had claimed the suet bar, and the juvenile's parent had been driven a few feet away to the railing, where it was waiting for the woodpecker to leave. The juvenile, however, was thoroughly freaked out, too clumsy or inexperienced to flee, scared AND ravenous, and didn't shut up for five minutes until the woodpecker finally stomped off (it's surely anthromorphizing to imagine him saying "Christ! I hate it when people take their kids out to eat and they scream the whole time!") and the pine warbler parent returned to pack suet down the shrieking gullet.
The number of babies that get brought to the suet feeder's pretty cool, though--I've seen woodpeckers, brown-headed nuthatches, Carolina wrens, and now the pine warbler.