Bees Flicker and Disappear

Bees will flicker in and out of hives, sometimes one by one but other times all at once. While somewhat amusing, clearly not intended. Bees will also just disappear over time. My hive of bees slowly trickles down for tens to at least a hundred to about 12.

Reproduce by putting a lot of bees in a room with a lot of hives. Effects can be witnessed then.