FWIW I just wait until they've all returned, and then cram a plastic bag in the entrance before moving them. Works for me!
Thanks kalium, that's a good tip.
Oak, what's the hose on top of the hive for?
That hose is used to pump sugar syrup from a tank on the back of a ute. The syrup fills the frame feeder which is along the left side of the open hive in the picture.