So I have been converting all floors in my base to bottom half slabs to prevent mob spawning inside my base. Is beautiful other than the fact that my bees keep getting stuck in the bottom of the bottom half slabs. 

To recreat this simply use only bottom half slabs between floors and the bees will get stuck in the bottom of the slab 

I am not sure if this is causing them to suffocate and die but I h 3 bees left of my 12 I had 3 days ago.