Too much moisture in the hive
Yesterday I when I pulled the drone frames out of the hives, I discovered the most populous hives were dripping wet under the cover. I had tried to prevent this by using upper entrances, but apparently the one-inch holes I installed were not big enough to keep the interior dry in spring.
Part of this problem is due to the weather; it has been rainy and cool for the last several weeks so it’s hard to keep anything dry. It’s also partly due to the populations in the hives—lots of bees mean lots of respiration and also lots of nectar collection. Everything, it seems, gives off moisture.
Moisture in the hive is not a good thing. Disease organisms, fungi, and molds thrive in moist environments and, in cold weather, water droplets can drip down on the bees and chill the brood. Proper ventilation is important for bee colonies year round. Bees can do really well in cold temperatures, but cold and wet is a different story.
I manage to keep my hives dry all winter with one lower and one upper entrance, but this time of year when the populations are huge and nights are still cold, it’s a bigger problem. So yesterday I removed the inner covers and replaced them with screen covers that have half-inch shims along the short ends. The shims prevent the outer cover from laying flat against the screen. The damp air can flow from the hive, up through the screen, and out the half-inch space on either side.
These screens greatly improve airflow but prevent insects—such as foreign bees or wasps—from coming in through the top.
After that was all done, I fed drone brood to the chickens—the ultimate in recycling! The nurse bees eat the pollen so they can secrete royal jelly and feed the larvae, and the chickens eat the larvae so they can lay the eggs which we can eat for breakfast—along with toast and honey, of course. What a system.