Dear everybody I find that bunging up the hive and pouring a 1/4 bottle of Vodka in the top kills them very quickly and arguably humanely. The frames can be aired to remove the vodka for a couple of weeks and then the frames can be given to other bees to clean up. As everything is food grade there is no problem..... except the lingering guilt, and the stress of having poured away good booze! Steve Pearce Kilspindie Scotland