SO! That's how...

. . . they did it?
Some time ago a "nearly-Blip" existed of a look down through the bag top. The little perishers hadn't exactly built a nest, but they'd had a good go at carpetting the seed surface. I couldn't work out HOW they'd managed it.
I had visions of Mousicopters and tiny scaling ladders & all sorts. I had
"NO eye Deer" how they leapt 10+ inches over the bag lip then out again. There was NO evident leak or a visible reduction.
Today I did a more extensive Feeder top up; NOT that I hadn't been doing it, just today I both, did all 3 and moved the bag.
The crafty wee beggers had, apparently, kinda Colditzed their way in with all their carpeting.
NO more! Warfarin to the fore. I  can't be harassed with catching them.