This is my first summer as a beekeeper. I put menthol packs in my hives several weeks ago. During recent inspections I have noticed that the bees have been working diligently to isolate the packs from the rest of the hive. They have put huge amounts of propolis between the frames underneath the packs and have also propolized between the edges of the packs and the inner cover. It seems that they will eventually totally isolate the packs from the hive. Is this typical? Is it necessary to go in to each hive periodically and clean out the propolis so the vapors permeate the hive? Rod