I was going to start a new thread but found this one which looks appropriate.
Sunday I hived a pair of packages into an 8-frame medium box. I put a top feeder with sugar water on top of the box, then a top board, then the cover. This morning I dug into the hives to check on the queen cages and there was a fair amount of comb in the slot between the two feeding areas. I scraped out that comb and some other burr comb. It never occurred to me they might use it as a ladder.
When I put the hives back together, I remember someone at a bee club meeting this winter say that putting the top board under the feeder will keep them from building the burr comb in the feeder slot, so that's what I did. Any other opinions? I guess I'll see how this works out in a few days. Only negative thing I can think of is maybe there will be a traffic jam in the relatively small opening in the top board. Maybe I shouldn't bother with the top board at all?