I am an urban beekeeping in Minneapolis on a typical city lot (40ft X 120ft). I keep two hives in my backyard. This summer I often noticed late at night when coming home that the garage flood light was on and there would be a handful of bees buzzing around it, like moths to a flame. In the morning some may be quietly standing near or around the light, but overall very much motionless, yet not dead. Some would also be on the cement walkway walking around seemingly groggy. It was odd behavior fr sure.
In the recent newsletter from my Beekeeping Association, there was an article about research being done in California for what they are calling Zombees. They exhibit similar behavior as described above and it turns out that the bees may be carriers of a certain species of fly's egg/larvae which grows inside the bee making them go somewhat mad. I was glad and scared that there was a reason for my bees behavior.
I have signed up as a "citizen scientist" and a made an inexpensive light trap. I encourage you also to sign up,be informed and see what sort of data sets you can provide these researchers. You can see their website:
zombeewatch.org.