Why Are There Dead Bees on My Hive Bottom Board?

Death is always a little jarring when you can’t explain it. It’s one thing to know that your bees go through a life cycle, like anything else, and it’s another thing to see it. Usually, they have the good sense to die out in the field, and the few that die in-house are removed before you come to visit. So when you find dead bees on your bottom board, it can be alarming.

This article will discuss the possible reasons behind the presence of dead bees on the hive bottom board and recommend appropriate actions to take when necessary.

Several factors could cause a high number of dead bees within a hive. Some reasons are relatively benign, such as natural die-offs due to aging, while others may point to more serious issues like disease, starvation, or pesticide poisoning. Identifying the underlying cause will help determine the best course of action to keep the colony healthy.

Common Causes of Dead Bees on Hive Bottom Board

Disease and Parasites

Varroa mites can weaken bees and infect them with viruses that eventually kill them. If a colony is affected by these mites, they can be found in the debris on the bottom board. Other diseases, such as American and European foulbrood or Nosema, may also lead to bee mortalities inside the hive.

Pesticide Exposure

Exposure to pesticides can also result in dead bees accumulating on the hive bottom board. When honeybees gather pollen contaminated with microencapsulated pesticides and return it to the hive, it can cause bee fatalities. 

Starvation and Dehydration

During cold or adverse weather conditions, bees may be unable to leave the hive to forage for food and water. If a colony doesn’t have enough stored honey and pollen to sustain itself, it can result in starvation-related deaths.

Bees that become dehydrated may not be able to thermoregulate their body temperatures and can suffer from heat stress, ultimately leading to death.

Temperature Extremes

In the winter, hives that are not insulated well enough may experience bee deaths due to cold temperatures. Similarly, excessively high temperatures can cause heat stress in bees, making it harder for them to maintain proper hive temperature, and ultimately leading to death.

Signs of an Unhealthy Hive

One thing to look out for is a bad or unexpected smell coming from the hive. This can point to issues like a high population of dead bees, mold growth, or even American Foulbrood, a highly contagious bee disease (LCBA).

Unusual activity at the entrance of the hive or inconsistent foraging patterns can indicate disease, starvation, or insufficient food resources. Inspecting the brood can also provide insight into the hive’s overall condition.

Lastly, the presence of pests, such as Varroa mites, can also be a sign of an unhealthy hive. A high mite count can weaken the colony, leading to diseases like deformed wing virus and eventually the death of the hive.

Preventing Colony Loss

Regular Inspections

Beekeepers should carefully inspect for signs of pests, diseases, and any other issues that could harm the bees. Hives should be checked every 7 to 10 days during the active season, and less frequently during the winter months.

Proper Nutrition and Hydration

Maintaining proper nutrition and hydration for the bees is essential in preventing hive loss. A balanced diet of nectar, pollen, and supplemental feed (when necessary) will help the bees stay healthy and strong. Beekeepers should ensure the bees have access to a clean water source and a variety of flowers, shrubs, and trees that support bee health.

Disease and Pest Control

Monitoring for common threats, such as mites, beetles, and foulbrood, allows beekeepers to take prompt action if signs of infestation or illness are detected. Utilizing integrated pest management techniques and treating diseases with appropriate medications when necessary is vital in preventing hive loss (source).


Dead bees on the hive bottom board can be alarming but not always disastrous. They may indicate a possible disease within the hive or simply an accumulation of natural deaths that haven’t been cleaned out yet. Examine the bottom board regularly and look for signs of deformed wings, which could imply a mite issue.

Another potential cause for dead bees on the bottom board is starvation. Bees can starve if there is insufficient food available within the hive, especially during the fall and winter months. 

Poisoned bees can contribute to this issue as well. However, identifying poisoned bees may require closer observation and a visit from the state apiarist. Where possible, get some samples to a lab for testing to know for sure.

Constant monitoring and thorough investigation can play a vital role in preserving the well-being of hives and the bee population.

Please Share!


Leave a Comment