I've posted many pictures on my project of the cheeky Blue Tits who dive down to the bottom of the feeders to grab whole peanuts - here's a good example: https://365project.org/vignouse/365/2017-01-06 The other birds are too big but that doesn't stop the more aggressive from trying - especially the Greenfinches. Mrs S spotted this one wedged solid upside down in the feeder with his legs and wing feathers sticking through the mesh. When I finally freed him he dashed forward, which was the wrong way as he ended up in the bottom of the feeder.
I finally extricated him and put him on the wall to recuperate, bur he was in a bit of a state as you can see here... he disappeared later and I just hope that he will recover enough to feed and look after himself.
This is for my PLAY project - you can read more about it in my profile - where I'll be using a different prime lens for each month of the year: for March it's the Fujinon 60mm f/2.4 Macro on an APS-C sensor camera (today the Fuji XT2) - the equivalent of a 90mm lens on a full-frame camera.