Bees fighting around entrance to swarm box

[BeeNice]

I have a few swarm catching boxes out, a 6 frame nuc box with one frame of used comb, one full hive brood box with all frames 5 drawn, and an empty super sitting on a floor, this one is just stored. All have bees going in and out for the past 4 weeks or so, but a lot of defensive action going on at the entrance of each box. Lots of bees not a sign of a swarm. Has anyone got an idea of why and what's going on as a lot of energy is being wasted in doing this by the bees.
ps. I have not bee hives close by.

 

[MartinL]

Scouts,

From at least two potential swarms.

Have a closer look and see if there's any noticeable difference in their appearance. That might give you a clue as to how many colonies are interested.

 

[REDWOOD]

Robbing, you probably have some honey left in the boxes

 

[Heather]

Robbing probably.

 

[oliver90owner]

Doubtful there would be anything left of stores remnants, if they have been visiting for 4 weeks.

Nucs are a waste of space for any decent sized swarm. OK for casts, maybe, or small swarms from overcrowded nucs, perhaps.

Tell us more about the decent sized bait hive - position, floor, entrance size and anything else that might make it more or less des. res.

Possibly a nearby apiarist carrying out A/Ss at the appropriate times?

 

[masterBK]

I agree with Martin L. Seen this loads of times over the years .

 

[BeeNice]

Thanks rab, thought of 2 hives having a look, bees different but you can find that in any hive, boxes on top of garage so 12ft up, no stores as all comb empty, brood box on solid floor, small entrance.
The 6 frame nuc has only the one frame so has a lot of space, but has as many bees having a look as the full brood box. It's just the fact that the bees have been around for such a long time that made me ask the question. Thanks for your forts!

 

[Tom Bick]

Four weeks sounds like passing interest the smell of possible goodies inside can cause bees to keep getting interested.

 

[BeeNice]

Tom, I think that's what it is. The promise only.