It's been incredibly cold here for a couple of weeks now (it was 4 degrees this morning). This afternoon I went out to look at the hive and, peering through the mouse guard, was shocked to see two icicles hanging off the bottom-front of two of the frames (right near the entrance)! They were small, one about as big around as a pencil, the other even thinner.
I can still hear buzzing coming from inside the hive, and I see dead bees periodically, so they're still alive. Is this anything to worry about? Maybe increase ventilation?