Re: Comb in Miller Feeder
I use the miller style feeder on my now four hives. I suspect that the screen, like all of ours, had a gap enabling the bees to access the space. I also suspect that the comb is drone, honey storage or re-purposed after the drone hatched. Either way, you most likely can't use the honey yourself.
IMHO, the best way to deal with this issue is to pull the feeder, set it next to the hive and cover so that it doesn't fill with rain but still open to the bees. The girls will harvest the honey and carry it back to the hive, which is exactly what you want. Birds will also make short work of any larvae.
When the girls are done, you can then carefully cut the comb from the feeder and claim the wax. Others cursed the plastic inserts for how easy a hive tool passes through. If you have the wire mesh like ours, I suggest removing it from the feeder and use a heat gun or similar to melt and reclaim the wax. I wouldn't use more than a hair dryer on the plastic feeder insert to soften the wax and be extremely cautious even with that. The plastic inserts last, as long as you don't mess with them. The screen on ours is #8 galvanized hardware cloth and is easily available in 20ft lengths at building supply houses. I once used regular fiberglass window screen for a similar purpose and found a big pile of little legs. I just replaced three rusted through screens by clamping the old one to the roll and cutting out a new one with tin snips. Then return the screen to the feeder and apply a bead of silicone caulk to the edge so that you do not have a repeat. I like leaving a small 1/4 inch gap in the silicone bead to prevent forming an inaccessible to bees puddle. The caulk doesn't have to adhere with any strength, just close gaps.
In past years I left the feeder throughout winter, but now I believe that can hinder ventilation. This year I'm going with the standard inner cover with small gap to the outside and storing the feeders elsewhere.
BTW, after each harvest, strain and/or bottling, I set all the sticky gear next to the hive out back and in a few days every drop of honey previously washed down the drain goes back to the hive and I'm left with a quick wipe down with dish soap and honey free wax for hand dipped candles. This year I also harvested throughout the season, which made an all day affair in the past an easy hour over several afternoons.
Hope this helps, good luck and keep us posted.