As with everything bees, there are different schools of thought on whether to do this or not, but if an attempt is made to beef up a weaker colony by adding brood frames from a stronger one, do you just swap in the brood frames leaving all the nurse bees on them? I assume so, as otherwise you'd be adding forces with no-one to look after them. How likely is it that the newly added bees on those frames would be rejected/attacked by the receiving colony? I have one of my 3 colonies that is lagging and I will have to decide soon whether to intervene or not if they are to get strong enough to overwinter. All 3 were started from nucs this summer.
cheers and thanks for any ideas and opinions,