Ventilation and the top bar hive

A major difference between Top bar and Langstroth hives is their approach to ventilation. A Langstroth hive is built like a chimney. The result is a large temperature gradient with heat radiating to the top creating a condensation effect that drips moisture down into the hive. Top bar hives are built horizontally and don't have this issue. In our hives, the window glass actually serves well as a condensation site, allowing the bees access to some water in the winter.

The bees themselves have a genetic ability to regulate their hive temperature. They do this by fanning -- it circulates air out the front entrance of the hive. Natural hives, obviously (!), do not have screened bottoms and usually just a small entrance hole. We believe a screen bottom board creates drafts which waft away the hive scents crucial to bee communication.

Seeing bees at night on the entrance is very common. They're regulating the hive temperature. The hive heats up as all the field bees return at the end of the day.

We have had people in warmer climates drill ½” holes covered with screening in the back of the hive near the top. The small size of the holes allows for ventilation while not preventing the bees from sealing the opening with propolis. Listen and watch your bees. If they propolize the holes shut then they didn't need them.

If your bees did not originate in your area (if they came in a package from Florida, for example), they may not have the genetic knowledge to seal their hive before winter arrives. If the bees have shown no sign of reducing the size of their entrance by late autumn, you can help them out by using a bunch of small sticks. The bees will be able to better regulate the hive temperature by opening the entrance to the extent they need.