Clustering outside the hive entrance (Not bearding)?

[Spear]

The bees from one of my hives are clustering alot outside around the the entrance and they don't all go in to the hive at night. A first I thought it was just because I put a queen excluder on so that I could find out for sure which of the 2 boxes the queen was in so I could move them to the new hives safely. So I decided to rake the excluder off and see if the 'problem' resolved itself but it has not. Could this be a prelude to a swarm?
I do plan on splitting hive ASAP - Hoping to get some new queens this weekend at the beekeepers weekend. I just hope they don't swarm before then...

Here is pic of the hives shortly after I worked on them - the one next to the red hive have all settled down but the one next to it is the 'problem hive':