WHY ARE THERE DEAD BEES OR PUPAE IN FRONT OF MY HIVE?

Photo Credit: Jay Dee - Reddit

Great question. As usual it depends. However in most cases it’s common to see a few dozen but it’s almost always an issue if you see hundreds. You will see some evidence of death almost year-round. Bees have a short life-span so bee death occurs every day. Anytime a bee dies inside the hive the others pull it out and throw it in front of the hive. On warm winter days it’s common to see workers pulling dead bees out of the hive.

However if you see hundreds it’s usually a sign of one of the following:

1. The hive is starving. A starving hive especially in the winter will result in hundreds of dead bees. Quickly look at your hive even if it’s cold to assess their food stores. If they are out of honey feed immediately. See “Winter Feeding” if it’s winter. If it’s not immediately feed syrup. If the hive has larvae or pupae they will cannibalize them or pull them out of their cells if they can’t feed them.
2. The hive has a significant Varroa infestation. Hives dying from Varroa mites will quickly lose adult bee population and will pull out dead or infested larvae. Test to see what your Varroa level is. If it is above two to three mites per 100 you do need to take action but it’s not enough to cause significant adult bee death. If the level is in the teens or above per 100 bees it could be the cause of the die-off. Quickly treat the hive.
3. The hive was sprayed with pesticides. If your hive has plenty of food and a low Varroa level but still has hundreds of dead bees it usually means they were sprayed. In this case there isn’t much you can do other than let them recover with time. One way to tell if your bees died from poisoning is to examine their proboscises (tongues) to see if they are sticking out. Poisoned bees often exhibit this symptom. You can give them small amounts of syrup mixed with an essential oil or probiotic mixture, as well as a few ounces of pollen substitute, to help them but usually they have to recover on their own. Occasionally a hive will have dead pupae in front of it because a spray made its way inside the hive or the larvae were fed contaminated honey or pollen, but these are less common.
4. The hive has gotten too cold. If a small hive gets too cold, adult bees on the outside of the cluster can die. If a hive has brood and a cold front comes through (especially in the spring), the hive can have “chilled brood.” The brood gets too cold and dies, and then the bees pull the dead larvae out of the cells.