Hi all. Yesterday I did my first hive inspection. I clearly left it too long as there was a lot of brace comb. Removing it resulted in a lot of comb getting broken away and it was a big old mess… Anyhow, the frames are all back in the brood box, with closer spacing than before. What I’ve noticed is that a couple of hundred bees persist on staying on the outside of the hive, all clustered around one side. When I looked inside the hive, the frame closest to the that side had a lot of comb on it (and perhaps the queen too, though I couldn’t spot her). I figured that may have been the cause for the bees remaining outside the hive, so I’ve rotated that frame into the middle of the brood box now. Have I done the right thing, or this not a good idea? What else could be causing the bees to cluster like that? The brood box has plenty of room, so that’s not it. Cheers!
I wouldn’t move a frame from the outside to the middle unless you are trying to rotate out old frames, and even then, I wouldn’t do it one jump (move it by just a space or two every week or so instead). They will probably cope, but you could disrupt the brood pattern and slow colony growth.
As to why they are doing it? Could be a number of things. If your weather is hot, they may be “bearding” on the outside. If you scraped off comb against the outside of the hive that side, they could be smelling hive smells or gathering honey drips. The last thought, I don’t even want to say… But, if the queen was accidentally squished against that side of the hive, they would definitely cluster there. I killed a vicious queen on a patio stone once when I was requeening a hive. It took a week before bees stopped clustering on the murder scene. I have modified my method since then… 
I suggest you look in the hive in a week or so for eggs, or young uncapped larvae. If you see those, then it isn’t the last reason. Meanwhile, if it was my hive, I would move the frame back to the outside, so that I haven’t rearranged all of the rooms in my bees’ house. 
Hi Chris, one thing to watch out for when doing brood inspections, if SHB is in your area, make sure you carefully replace the frames, being careful not to wedge any bees between frames or comb. Make sure you have a decent bee space on the outside of the outside frames.
SHB larvae will drive the bees away from the brood because the SHB larvae exudes a slime which is a bee repellent.
I keep the drone comb in my brood to a minimum. Drone comb is a magnet for SHB to lay eggs in.
The more worker comb you have in the brood, the more workers you’ll have in the colony. The more workers you have, the better chance you have of stopping the beetle from infesting your hive.
“Why are there bees on the outside of my hive?”
Thanks all, really loving all the good advice here, it’s fantastic. I’m beginning to think they may be mainly cleaning up remnants from my rather messy and comprehensive removal of burr comb yesterday. There was a lot of dripped honey. There’s still probably a couple of hundred outside the hive, but they’re not so concentrated as before. I’ve removed the bottom board to allow more cooling airflow into the hive too, as have had a hot run of days in Sydney, so that could be contributing too. Cheers once again.
here in Dallas TX. it is 4 hours after sunset it is 76°F and just when out an looked at the hive and there were about 30+ bee’s on the outside of the entrance, moving around slowly. NUC was installed in the box on Saturday, so there should be more than enought room. The entrance reducer is inplace and the feeder also, have the bottom board in the top slote of the screen bottom board
any thought on why they are outside, anything I should do or NOT?
Have another beer, and don’t look in the hive. 
They may be cooling off, or if you have bright lights near the hive, they may just be disturbed like birds are by human night time lighting. Turn off the lights and sing a lullaby. They will be fine, don’t worry.
Dawn 
Thank you to you both, yes I just went to bed 
this morning went out and checked the girls and everybody was inside. This was about an hour before sunrise
Check out some videos on washboarding. I’ve seen my bees do this and I’m not sure we know the reason why they do.