We live in an area where history is dominated by the English Civil War and bees follow in that tradition. If you simply add one colony on top of another they will set about killing each other. If, on the other hand, you spread one sheet of good newsprint over the host colony before adding the new one above things are different. The bees will within 48 hours, chew their way through and, like Channel Tunnellers, greet each other on the other side with open wings and no conflict. Incidentally I wonder if the newspaper pubishers appreciate the consequences to our honey bees when they trim their page sizes.
Inspection 8 days ago revealed that hive 2 was still queenless after more than 4 weeks. Not having a spare queen or young brood to introduce I decided to unite it with hive 3 where there is a laying queen. the newspaper method worked a treat and yesterday's inspection revealed lots of contented bees and chewed newspaper. So now we are back down to 2 colonies, lets hope this beautiful weather gives them a boost.
Incidentally the "extension" underneath hive 1 was successfully dealt with by placing a tray underneath and gently brushing the bees off with a feather. They were then poured into the top of the hive. The unwanted comb was then scraped off and collected for melting down.