When I put the jar feeder on my follower board I didn't expect the bees to cluster around it. But after recently installing a package that's what they've done. Now I can't see if the jar is empty. What should I do? Break the cluster and smoke them off the jar? Bee brush them off? Also I'm sure they're building comb above the jar and surely that won't turn out good when it reaches the top of the feeder. Suggestions?