Dawn behavior

[Docpelletier]

I'm a fairly new backyard keeper. For 2 of the last three mornings, right about dawn, we found a dozen or two bees flying energetically at our N-facing window, which faces our hive. One or two have gotten into the house. I have checked for any activity around vents and gables etc. It does not seem as though we have a colony in the house anywhere.
My initial hypothesis is that a rodent or some other pest got to the hive or near it during the night, early morning, leading to a bunch coming out aggressively to defend the hive, then ending up against the warmer windows.
Anyone have any better ideas?

[iddee]

If they are coming to a light, you may want to check this out.

https://www.zombeewatch.org/

[Bob Wilson]

My guess is an inside light is on the night before, which attracts bees to your bright window. When you turn off the light at bedtime, the bees get stranded there in the dark. The early morning sun gets them active again.
At least, that's what happens with my shed windows when I work after dark.
Test it by keeping that room unlit one night and checking the next morning.

[Acebird]

My guess is an inside light is on the night before, which attracts bees to your bright window. When you turn off the light at bedtime, the bees get stranded there in the dark.

Bees see pretty well in the dark.  Tip over a hive at night if you don't believe me.  They find you by following your heat signature.  The hive cluster is a very strong heat signature at night.
Up north we had an automated billboard about 100 ft from my hives.  You would think all the bees would fly to it at night and die.  I never saw a one and I looked for about two months after I got my first hive.  Think of the millions of street lights that glow all night long.  I don't know why some insects fly around lights and die but most don't.  My only guess is that they are near end of life anyway.

[Bob Wilson]

I didn't think of that, Brian. I just seem to have bees on hanging onto my screen porch the mornings after I leave the light on, and my hives are 20 feet away from there, so I just assumed they get stranded.

[BeeMaster2]

When I lived in Jacksonville with 10 or more hives in my back yard, every time I turned on my bathroom light, within a few minutes I would hear the bees buzzing at the window. Not a whole lot but 5 to 10 would end up at the window.
It doesn?t mean the hives were sick, it is just that with 40,000 bees in each hive there is always a tiny fraction of that number of bees that are attracted to the light. The hives were about 50 feet from this window. If the light stayed on all night, the bees would bee dead in the morning. If not they would bee hanging onto the screen until they warmed up enough to fly home.
Jim Altmiller

[The15thMember]

I think something relevant to mention here is that bees are not attracted to all lights, but only to lights that emit UV radiation.  For example, I store my bee equipment in my garage, and if the door is open the bees often wander in there in the fall and investigate the boxes.  If the incandescent light on the garage door opener is on, they aren't attracted to that, and will totally ignore it.  But if the florescent tube lights (which emit light at the UV wavelength) are on, they will fly right to them and keep flying at them and bumping into them until the lights go off.  I think it has something to do with the fact that bees navigate by the sun, and UV light from another source can screw up their navigation system.       

[Acebird]

There is another difference between florescence and incandescence.  Florescence bulbs flash at 60 cycles per second.  We can't see that maybe they can.

[beesonhay465]

i have a 500 watt lamp like a work lite with a bulb about 4or 5 inches long . any bee that sees it on will fly to it and be fried.

[TheHoneyPump]

There is another difference between florescence and incandescence.  Florescence bulbs flash at 60 cycles per second.  We can't see that maybe they can.

A few of us can.  I can definitely see the 60Hz signal. Flourescence drive me nuts with eye strain from the flicker (which most people cannot see), headaches, and irritability.  At my professional workplace, the lights in my personal office are always off and windows are cleared for daylight.  I also have the same issue with most computer monitors.  I have to buy ones capable of 85Hz and turn them up to that.
Give me sunlight, firelight, incandescent (halogen pref) or (some) LEDs.

Fyi.  The city street lights above the fence over my backyard do not draw bees from those hives which are about 30 yards away.

Perhaps a window reflection of the sun is a possibility with those bees.  Where is the sun in the morning at that location relative the window and the hive. Is it possible that the window is reflecting the sun onto the hive much like a mirror?

[Acebird]

I also have the same issue with most computer monitors.  I have to buy ones capable of 85Hz and turn them up to that.

You could do the same with lighting. Change the lights to the more modern type that cycle 20,000 to 60,000 per second.