Very strange problem with one hive - bees clustered on ground
I have an 'issue' with one of my hives that I've never seen before... Hoping for a bit of advice.
I have three hives in my yard. 2 are behaving normally and are issue free. But with the third there are bees all over the ground around it in about a 10' radius. Hundreds of them. The bees seem unable to fly if I blow on them but they will buzz and try to get away. They tend to be clustered together in little groups and appear to be grooming each other in the group. I cannot see any DWV or K wing, cannot see any visible mites, and this hive had the lowest mite count of the three last year. They do not return to the hive at night, and since it is so cold at night still they are dying at night.
3 weeks ago we were still in the low 30's and today we were in the mid 70's so I suppose they could just be hanging out. But the fact that they won't fly away and won't return to the hive tells me something is up.
Has anyone seen this before? I would guess pesticide exposure but the other 2 hives are behaving normally. This one is closest to my neighbor's fence and has an exposed entrance to their fence (forcing them to fly up) so it's also possible the kids next door did something to the hive. Can't smell any residue though.
Thanks for any advice you can give. I'll try to take video or photos tomorrow.