Take a look at the photo above. It shows the entrance to a beehive that is in our backyard in Seattle. The place where the bees land as they come into the hive is covered in a damp dirty substance. It is probably a mixture of dirt and mildew. This hive is dead. I don’t know what it died of but then lots of beehives die in the winter since the verroa mite came into the area. Compare the landing board above to the landing board of the very much alive hive pictured below. The bees somehow keep the landing area clean. I don’t know if they clean it or if in and out traffic keeps it clear. (Picture a matronly bee on her bee’s knees with a brush and a pail of water!) The difference in the appearance of the the landing board has for me become a pretty good indicator of which hives have died over the winter.
If the hive is alive, the bee landing board at the front of the hive is clear and clean.