Dish of bees under OMF

[cwinte]

Is this familiar to anyone? I had it several times last year, with one hive it went on for several summer weeks.
Today, rather cool & some heavy showers with sunny spells, many bees exited to front of hive around noon (1pm GMT) and then moved themselves under the hive OMF forming a dish/plate mass about 25cm/10" across and 5cm/2" deep in centre.
I have been waiting for the best day to do next inspect and planned for tomorrow: the warmer, sunny Sunday 2nd. Last detail inspect just 1 fun cup and looking regular on 19/4 and quick between the boxes look on 26/4 did not reveal any cells or large drone zones.
I will keep an eye from time to time but suspect those under will remain under. Most other bees are just normal foraging etc and ignoring the dish. One or two join them every few minutes by crawling down.

I could try and gather them to waiting brood box.
Last year I had 2 or 3 Q- sessions between 2 colonies (and a recombined split) where Q just seemed to go absent. It seemed like a Q might have left scent under as it remained an attractive place for many weeks.
I wonder if HM might be in that dish - perhaps they were emerging to swarm but put off by rain and cool?...

Any thoughts?

 

[Ian123]

Quite normal with mesh floors. They can obviously make contact with each other but don’t quite grasp the concept of mesh, they work it out eventually.

 

[enrico]

They are underflying the entrance. This comes up every year. Block off the area from the landing board to the ground and it will stop. You can lose hundreds of bees on cold nights. You will see them on the ground in the morning. Just brush them onto a board and let them crawl into the entrance.
They don't know why they can't get through the OMF. They think they are on the hive!

E

 

[WoodenBeam]

Get it with clipped queens. Attempt to leave the hive, fall out and then climb back up under the hive.

 

[cwinte]

OP update on what I see

Get it with clipped queens. Attempt to leave the hive, fall out and then climb back up under the hive.

My queen not clipped (by me anyway) but my feelings are along these lines.
This morning at 9am, chilly but sunny here, there is a steady flow (4 to 6 at any moment) of bees walking out of the hive, down the 4 inch cross beam of my stand and backup underneath to join those that were there overnight. Overnighters were a small mugful at 7am, now there are about 10 times the amount.
Does feel like some swarm related process rather than a few getting there by mistake, and too cold to be a bearding or cooling thing.
It is on my list to go into hive today to inspect but wonder if I should wait until the group maximises, sometime 2-4 maybe, and treat it like a swarm collection and put the mass into empty nuc or hive. Then see what they do and look for the Q later...

 

[cwinte]

OP: moved the group under OMF at 2pm

Just lifted whole hive (at the limit of what I could lift) off the OMF and then shook bees into spare bait hive.
Looks like there was no queen as they left in 2s and 3s to fly home. 2 hours later there are still a few bees leaving.
Currently there are no bees under the original OMF that I shook off.
Sort of cleared the issue up for me.
Last year they started to build comb under the OMF so hoping to preempt that.