I have a low population hive that's presently in a nuc and am looking at 30s for the next few nights. I just want to knock the edge off the cold to keep the brood from dying since there probably is 3 total frames of bees in it. I am planning to place an 8W terrarium heater under it tonight after experimenting with an identical empty hive last night, making sure I wouldn't overheat my bees. It kept the hive around 70 when temps got into the upper 50s.
Question is could they actually think it's balmy out when it's actually in the 30s? So field bees end up taking off and then never make it back?
Don't know how heavy the hive is but the two hives I have are also small. One has less than 2 cup full of bees. I close them up when its going to get below 35 and put them in my garage. I also, when it's nice out side, take the top off and pour honey on top of the frames so the can put it directly into the comb. Just a trinkle on top, not enough that it runs over the side of the comb.
I have an observation hive in my living room most winters (didn't this winter because I never got around to setting it up again) and they always know when it's cold outside. They don't fly out and they don't get carried away rearing brood, but they will raise a small patch from time to time. Some bees fly out of any hive from time to time when it's too cold. I never understood why, but there are no more because of the heat.
Tracy,
I use two 7watt night lights (14W total) and have never had a problem with the bees flying when it is too cold. I even do it with polystyrene hives which run about 10 degrees warmer than wood.
Strong hives will fly sooner when heated, when the temperature is marginal.
rob...