That would be Pollen Plugged Frames. We have an unseasonally early spring. The bees are giddy with bringing in a ton of pollen and plugging up the frames. I remember going thru this about 4 years ago. The problem is, is that the bees will not remove the pollen, ever, so the queen quickly runs out of room. In our neck of the woods, swarm season is coming early.
In the mean time, we beekeepers are stuck with many frames and all that drawn wax, that isn't of any use when plugged up.
How do we get the bees to remove that pollen? Or, would you take the time to dig out each cell? that would be a laborious job!