I'm positive I had fish feeding over my bait this week, in fact this morning, but I felt because it was over birdfood and Vitalin they weren't picking up boilies, so with previous sessions in mind I had ordered some treats for them for hookbaits.
The massive flat patch is where one of my baits was, but a snowman hookbait, 15mm pop-up over an 18mm bottom bait, not a bleep. I'm pretty positive it was carp clearing the smaller food items.