Bees in grass
I have recently noticed this behavior that has me worried, but I am having real trouble making sense of it. In effect, it is this: this evening, after a very warm day, my bees did a late orientation flight. That's normal for my bees. However, after orientation, I noticed bees in the grass around the hive. Now, I've seen a few of those before, but this time I lingered and just noticed that it was quite a few. A few dozen, near the hive, climbing blades of grass, falling over, climbing up again, and then at some point just sitting where they were. By this point, it was dark outside, The hive itself has the normal amount of bees — given the weather — populating the front of the hive.
The bees in the grass were just sitting there. I checked for abnormalities — I could get real up close and picked some up with my finger to take a close look — and saw nothing abnormal. No abnormalities on the abdomen, no visible mites, normal wings — not tattered or deformed. I also have to stress that I've seen similar behavior before, but never noticed it on this scale. But this is also the first time I really went looking for these bees in the grass.
The hive itself seems quite healthy. Right now, I have two quite full brood boxes and a super with comb being drawn and covered in bees. Daily orientation flights are busy. Bees are coming in with pollen and nectar. Healthy looking queen and evidence of active laying.
I did my research, but it's confusing: many posts indicating that this behavior is evidence of tracheal mites, but then I found credible sources debunking that completely — government extension offices as well as journal publications. I am satisfied that this is not behavior caused by tracheal mites as people used to claim. I have no evidence of varroa in the hive. Moreover, those bees in the grass are not actively dying, and there are no piles of dead bees, so I have no reason to suspect poisoning.
None of the books I have have helped me, and digging through forums has been generally unhelpful, with people claiming this is clear evidence of tracheal mites — which I really do not believe is the case — to people saying that it's perfectly normal for older bees to remove themselves to die, and then other people indicating that they would usually do that further away from the hive. These are all within three feet. Notably, none that I have seen have pollen baskets, which are being brought into the hive right now. Then I've seen a bunch of posts from people who claim that it's just bees who miss the hive upon their return, will overnight, and mostly revive in the morning.
There are so many different explanations out there, evenly spread between doom and gloom and 'nothing to see here' that I am truly at a loss. If there is an intervention I need to stage, I would like to do that, but so far, it is unclear to me what — if anything — I should be doing.
Any insight would be greatly appreciated.