I noticed something unusual yesterday. I happened to touch the top cover of one of my hives and it seemed warm. Warm on a typical frigid April day in Newfoundland. So I pulled the top off and put my hand on the wood chips in the moisture quilt…

A hive giving off some heat. (April 15, 2016.)
…and that sucker was giving off some serious heat. I’ve felt heat over the moisture quilt in the winter in strong colonies that were clustering near the top, but never this late in the winter. (On a practical level, my winter beekeeping doesn’t end until it’s warm enough to give the bees sugar syrup, if necessary.)

One seriously hot hive next to my bee supply shed. (April 15, 2016.)
It might not mean anything, but it could mean the queen has been laying and a big batch of brood recently emerged. That’s just a guess.
I took a peek under the moisture quilt and it was packed with bees all over the dry sugar and devouring a pollen patty I threw in about a week ago. I’m not sure what to think, but to feel that much heat coming out of a hive at this time of year — it’s a new one for me.
UPDATE (the next day): After inspecting the hive, I did find a frame a brood, though overall I’d say it’s a fairly small cluster for this time of the year. Whatever is going on, nothing bad seemed to have come from the heat. Strange.
I think I’d take heat over cold! Glad they are alive and making new brood!