Assessing Honeybee Colony Size

No matter the reason for your trip out to your bee yard and inspection of your colonies, each time you peek inside one of your beehives you should always be thinking about how many bees are inside.

Obviously, you can’t count each one, you’d be there for days! But there are other ways to get an idea of how many bees are inside. Knowing the size of your honeybee colony and understanding the ‘frame of bees’ concept is critical if you aim to help your bees to not just survive, but to thrive.

Why Does Colony Size Matter?

If you have an estimate of not only how many bees are currently in your hive (read on to learn more about determining size with the ‘frame of bees’ or FOB idea) but whether the colony’s population is growing or declining, you can learn a lot about your colony and their health.  

Continually monitoring colony size allows you to better help manage their health and detect any issues inside the hives much sooner. A declining colony can indicate a much bigger problem, like a possible Varroa mite infestation, diseases, or queen productivity issues. Keeping a close eye on the brood box and brood pattern can help you to identify and address concerns sooner, too.  

Not only does assessing colony size give you the chance to gain a better understanding of your colony’s health, but it also gives you the chance to help them better manage their space and resources and prevent swarming. If your colony is growing too quickly for the space available and you haven’t realized just how many bees are in there, it could lead bees to feel like they don’t have enough space and may swarm.  

What Exactly Does a “Frame of Bees” Mean?

A “Frame of Bees” (or FOB for short) is a measurement used by beekeepers to help estimate the number of bees inside a hive. As any beekeeper knows, when you open a hive to inspect them, it becomes a bit chaotic. Bees are flying everywhere and moving throughout the hive, but inside the brood nest, most bees on the frames will stay there, even as frames are removed.  

By reviewing the tops and bottoms of frames to see how many bees are present, or by counting any frames you’ve removed that are completely covered with bees, you can get a rough estimate of the colony’s population. 

It’s important to keep in mind that a colony’s size is NOT determined by the number of boxes or how high the hive is, it’s wholly dependent on the actual amount of bees inside.  

The below image created by the Bee Informed Partnership does an excellent job of further explaining how FOB can be measured:  

Determining if the number of “FOB” that should be present in your hive will depend on the style of hive used (many guidelines are based on standard Langstroth hives) and the number of frames that are in each box.  

As an example, a colony in a 10-frame hive is typically considered strong and healthy when they have at least 6-8 frames of bees inside each brood box during the spring months. If you’re completing an inspection and notice only 3 frames full of bees, it should indicate right away that there could be a problem and prompt you to further investigate and help your bees to fix it.  

These figures focus on the current colony’s population size, but it is also important to use the current FOB in the brood nest to estimate the population growth potential. For example, a colony with 8 FOB and 6 brood frames will likely double in size within 2-3 weeks, depending on the amount of capped brood. If left unchecked and there’s not enough space, this could easily trigger swarming activity. On the other hand, the same colony with 8 FOB and no brood present will indicate colony trouble over the coming weeks, causing potential issues like a brood break and interruption in colony growth.  

Beekeepers should develop the habit of assessing their colony’s current size and potential for growth simultaneously, at least a few times per season to better understand their colony’s growth stage. 

When is Monitoring Colony Size the Most Critical?

Knowing the size of your honeybee colony is quite important at any time of year, but there are certain times when it’s exceptionally critical.  

Here are a few examples of when & why:  

• Seasonal Considerations – The total number of FOB in your hive will vary depending on the time of year, so it’s important to take that and the weather into account. In the Spring, colony size should be rapidly expanding. During the fall months, colony size will begin to decrease until the winter, when the colony is at its smallest. Going into winter, FOB still matters as the colony should still have enough bees to survive through the winter in their cluster. Summer months mean your colony should be at its peak, a large, strong colony with many frames covered by bees. 
• Think About the Nectar Flow – During the early summer months, rapid brood production often coincides with nectar flowing into the hive. Ensuring the colony is at its largest during this time means they can maximize honey production. Be sure to keep an eye on not only the FOB in your hive during this time, but also the frames with available space for nectar/pollen storage AND egg-laying.  
• Mite Treatments & IPM – A high level of any pests inside the hive, especially Varroa mites, can impact colony size and stunt their growth. Noting a decline in population growth can help you determine the impact of pests, diseases, or mites on your honeybee colonies.  
  • Some mite treatments may also have special considerations based on FOB and colony size. Ensure to read the EPA label and all considerations/regulations of your chosen mite treatment thoroughly before applying it to your colony. Read more about mite treatment considerations in our Snippet here.  
• Winter Preparation – If there aren’t enough bees in the hive going into the winter months, they won’t be able to keep warm or access food stores and will perish. Keeping a close eye on the size of the colony in the late summer and early fall months can help you and your colony better prepare for the long winter ahead.  
• Emergency Feeding – During pollen/nectar dearths or long periods of bad weather, and during the winter months when bees are unable to leave the hive, the amount of food stores they are consuming may be impacted. A larger colony will consume resources much more quickly and may need supplemental feed before a smaller colony would.  
• Commercial Beekeeping Considerations – For beekeepers who provide pollination services or produce honey commercially, keeping track of the size of colonies is a necessity. Only strong, densely populated colonies can effectively complete jobs like pollination or produce honey at high levels.  

Not just knowing, but also understanding, your colony’s size and what it means, especially during the above circumstances, can help you to make better beekeeping decisions that will aid in your colony’s health and success.

Making Note of Colony Size

As with most beekeeping tasks and considerations, taking notes and keeping good beekeeping records can make a huge difference in the success of your hobby and your colonies.  

Ensuring you note the colony size and FOB present after each visit to your bee yard will help in your beekeeping tasks in the immediate future but can also help you to make better beekeeping decisions in seasons for years to come. Taking photos of frame tops and bottoms can be a big help in counting FOB, too. Read on to find some resources on taking good notes during your inspections in the “Learn More” section below.  

What if the Colony is Too Big? Or Too Small?

Being able to determine whether your colony is either too large for their current hive setup, or too small to remain successful, is incredibly important and can help you effectively manage your hives. Colonies that are too large may need to be split and those that are too small might need to be combined with another stronger colony to have a better chance at survival.  

Keep an eye out for an upcoming Snippet where we’ll cover managing hives that aren’t quite the right size and the tasks that help you to better manage them. 

Learn More

Check out some of our additional resources related to assessing colony size below.  

• Inside and Out of the Beehive – In this lesson, we dive into the fascinating happenings in and away from the hive and touch on the important timing of a colony’s population growth.  
• Why and How Bees Swarm – Knowing your colony size can help manage swarming activities and ensure colonies have enough room. Learn more about swarming with our lesson.  
• Managing Hive Capacity – The size of your colony can have a direct correlation to the amount of space they have available inside their hive.  
• A New Beekeeper’s Journal – Bee Colony Growth Spurt – This post covers various aspects of recognizing what’s changing with your colony’s population growth and how to handle it.  
• A New Beekeeper’s Journal – Buckfast Bees, More Splits… – Find out more about how to handle a colony that’s getting too big in our blog post.  
• A New Beekeeper’s Journal – The 2^nd Half of Summer and Your Bees – Learn more in this post about what happens with colony size toward the end of summer and the beginning of fall.  
• How Taking Notes Can Help Manage Varroa Mites – This Snippet is geared toward note-taking and Varroa mites but has some great points on taking notes, in general, to help you easily keep excellent records of the size of your colonies.  
• Effectively Managing Space in the Brood Nest – Having an idea of how many bees are inside your hive makes it much easier to help them manage the space available. 
• When Advanced Monitoring Meets Beekeeping – Hive monitors that measure the weight of your hive can help determine if the population is growing or dwindling. Learn more about hive monitors in our blog post.  
• A New Beekeeper’s Journal – Hive Inspections & Recordkeeping – More on the importance of taking detailed beekeeping notes and some practical tips, too.  

PerfectBee Store Products Related to Assessing Colony Size  

It might not be easy to get a headcount inside a beehive, but the PerfectBee Store has some awesome products that might make the job a bit easier. Check them out below! 

• SolutionBee HM-6 Hive Monitor – Easily gain important hive data, like your colony’s weight, sent straight to you remotely. Knowing the weight of your hive and paying close attention to any fluctuations can help you proactively manage colony size.  
• BroodMinder-W Weight Scale – Another excellent option for hive monitoring, the BroodMinder-W will weigh your hive and send details to your phone automatically, giving you the chance to get ahead of any potential colony growth issues. 
•  Swarming: Control & Prevention – If colony size isn’t managed or growth gets out of hand, swarming is possible. If you’d like more help with that subject, this guide is perfect for you! 
• Hive Management – Another excellent guide for more information on managing colony population growth and colony size assessment.  
• Honey Super Kit – Is your colony growth getting out of hand and fast? Do they need more room for storing honey? Pick up a honey super kit to easily add additional space to your colony, fast!  
• Swarm Catch Lures – If your colony’s size gets out of hand before they swarm, you might be able to lure them back to a box (especially if it’s up high) with swarm lures. Keep a swarm catching sack on hand, too, just in case!  

Colony Member Resources

Colony Member-Only Academy Lessons 

Colony members, check out some of our member-only Academy lessons below to find out more about your colony’s size and what it may indicate.  

• What is Bearding in Honeybees? – Often an alarming sight, bearding can tell you a lot about your colony and its size.  
• Splitting a Hive of Bees – When a colony’s size gets to be TOO large, splitting them into two colonies may be the best option. Find out more about the how and why of splitting a colony in our lesson.  
• How Bees Manage Temperature and Moisture – A colony’s size has a huge impact on the temperature and moisture in their hive. Learn more about how bees work to keep the temperature and humidity at just the right levels.  
• An Introduction to the Brood Nest – More details on how many bees, what type of brood cells, and egg laying pattern you should see inside your brood nest.  
• Fat Bees and the Winter Cluster – Knowing your colony’s size ahead of the winter months, especially in cold climates, is so crucial. Learn more about the winter cluster and how bees work together to survive. 
• Beekeeping and Technology – Dive deep into the way beehive data can help guide your beekeeping tasks & aid in your and your bees’ successes.  
• Preparing for Deep Long Winters – Having a healthy-sized honeybee colony going into the winter months gives them a much better chance at survival. Find out all you need to know about preparing to overwinter a hive in this lesson.  

Colony Forum Posts 

Members of the Colony Forum often ask about whether or not their hive would be considered a healthy size. Members, read through some colony size related threads below!

•  Swarm/New Colony Mite Treatment – Paying attention to colony size when treating for varroa mites is crucial. Kevin smartly asks about a small swarm and what treatment might work best. 
• The Flipside of our First Winter – Tracy shares some interesting comparisons between her larger and smaller sized colonies and gets some great answers to her questions about how to proceed with certain tasks.  
•  Weak overwintered colony – Kevin gets some help in determining what might be affecting his colony’s population after a difficult winter.  
• Poisoned bees in February? – Another threat to a colony’s population growth and health could be exposure to poison or pesticides. Ambassador Ron shares his insights on a difficult situation he faced with a now very small colony.  
• 1st Inspection of the year and… 🙁 – Vincent shares some photos and insights into his small hive and gets awesome guidance on how to help them out.  
• Why mites pick certain hives? – Jay asks a thought-provoking question about colony size and its impact on varroa mite infestations.  
• Adding a queen to a failed split – Even with a failed split, if it’s not too late in the season, helping your colony get to a healthy population is still possible.  
• Drones, drones, drones! Can’t see the Queen! – Sometimes the type of bees that make up your colony size can be important, too! Donna asks about why she’s seeing so many drones and gets some great input from our Ambassadors.  

Do you want to know more about bees & beekeeping and wish you had access to learn more through online beekeeping resources? Look no further! Colony membership provides you with the tools and education to keep learning all you can about the wonderful creature we all love, the honeybee!  

Plus, you get a chance to connect with a friendly community of beekeepers through Colony Forum posts like the ones above, our live Cluster events and so much more! We’re a bunch of passionate beekeepers who all just want to help each other. Discover more about Colony & all the benefits of membership here.