When we had one a couple of years ago I was told by a couple of bee keepers I know that they will move in 3 days, they have enough food with them to survive and they will have scouts out looking for somewhere to move to.
They were no problem while they were here but the bloody big cloud of bees when they arrived and left was a bit worrying especially when I was in the shed and I heard next door shouting their kids in because of all the wasps. I locked myself in at first but the little shits were landing next to my kennels so I legged it to rescue the mutts.