It's taken them a while to find it, but they've eaten all the fat balls and had a wee taste of the peanuts but ignored everything else, the ungrateful little tweety fuckers.
ETA: pmsl. I put new fat balls out, put the debris in the bin and then went downstairs to put the recycling in the bins. Downstairs, I looked up at the feeders and realised why the fat balls all disappeared within a week - a very agile crow (well, maybe - black feathers, black beak, black legs) was hanging from the feeder and having a good go at the contents.