3 screen pieces on the feeder
Acts as a ladder and keeps the bees from going under the divider (A) and into the feeder well where they might drown. There are really three screens. Two are the ladders between A and B and the third is the cover that spans A to A. With the cover in place you can fill the feeder without bees flying out. I also made a screened cover for the whole affair. Often times your telescoping cover won't completely seal the feeder and you get bees coming under the cover and drowning in the feeder wells. You can fill the feeder through this screen and remove it if you need to clean the thing out.
Hope this helps,