Strange behaviour

[Maz1]

Hi all, I put a large swarm into a nuc about 48 hours ago and this evening I noticed a cluster of bees in the grass about 8 ft from the nuc entrance. The bees are alive and are very much balled up. The nuc now seems very restless with bees moving around by the entrance even though it is dusk.
Any ideas?

 

[Ian123]

Could be queens in the cluster outside, could even be a queen in the nuc if it was a cast with multiple virgins