Bees swarming into occupied hive

[WingCommander]

So this has just happened to me.

I have a very weak colony in my garden that I rescued lat last year. I wasn't sure that I had managed to get the queen in the rescue (from a compost bin) but after the winter they were still going, spotted the queen and there was a small amount of brood. I've generally left them alone to rebuild but went in less than a week ago to check on them - still very quiet.

Just looked out of the kitchen window to see substantially more bees on the outside than there have ever been on the inside of the hive. Checking in with my bee buddy and he initially reckoned that it could be bearding but there are just too many. We decided that it was probably a cast (due to numbers) and that we would combine with the existing weak colony and let them sort it all out. I popped into the hive and opened the roof to find the inside packed with bees - they had already moved in! I assisted the remaining stragglers, swiveled the entrance to the QE setting and will let them sort it out amongst themselves!

Anyone heard of a swarm taking an occupied hive and also thoughts on what I did and what I could expect going forward.

Photo attached of the bees on the outside prior to operations commencing.

 

[Pete D]

Yep, last spring, small 4 frames of bees in a full national, dummied but with all frames in. On weekly check saw the queen, smallish and dark, not marked.
The following week I looked again expecting not much progress and the hive was full, bursting with bees. On looking through I found a large queen marked red, I didnt even own a red pen at the time.
Gave them a super, then another, a few weeks later after giving me 50lb of honey they were gone again !
Somebody living near to me had obviously invested in an imported queen early in the season and she was the swarmy type. Or of course they only had a red pen !

 

[WingCommander]

I now need to upgrade my Nuc to a proper hive!

 

[user 6228]

had swarm attach itself underneath an occupied hive. They were evenly matched. We managed to separate them before too many bees were lost ( a few hundred)

 

[John R]

I had a problem yesterday, I have 3 hives, hive 2 was swarming in front of it's hive on the grass and started to clash with the bees from hive 3, I lost a couple of hundred bees. Both hives are strong and I've never seen this before, my bees have never taken much notice of each other.
The mock swarm ended up going back into their original hive, but they're not settled and seem to be massing around the base of the hive to only go back in again.

 

[Skyhook]

I had a problem yesterday, I have 3 hives, hive 2 was swarming in front of it's hive on the grass and started to clash with the bees from hive 3, I lost a couple of hundred bees. Both hives are strong and I've never seen this before, my bees have never taken much notice of each other.
The mock swarm ended up going back into their original hive, but they're not settled and seem to be massing around the base of the hive to only go back in again.

Do you clip your queens? Sounds like a swarm has issued, the queen has nose-dived, and they're trying to work out what to do about it.