Several hundred bees in rural Pennsylvania and New York now have tiny QR codes affixed to their backs to monitor their movements in and out of their hives. This initiative, a partnership between entomologists and electrical engineers, aims to uncover the longstanding question of how far bees travel to gather pollen and nectar.
In rural regions of Pennsylvania and New York, several hundred bees have been fitted with tiny QR codes on their backs. These tags are not just a quirky trend in bee fashion; they serve a vital scientific function: tracking the timing of honey bees’ foraging activities outside their hives. This research is part of a collaborative effort by entomologists and electrical engineers at Penn State, marking the initial phase toward solving the enduring enigma of how far bees venture from their hives to gather food.
The researchers have discovered that while most bees conduct their foraging trips that last only a few minutes, a smaller group of bees can stay out for over two hours. With the advanced tracking system developed by this team, they anticipate gaining even greater insights into the foraging habits of honey bees.
“This technology is unlocking new avenues for biologic research that were not achievable before, especially in the realm of organic beekeeping,” explained Margarita López-Uribe, the Lorenzo L. Langstroth Early Career Professor and associate professor of entomology. She is one of the authors of a paper published in HardwareX, an open-access journal that describes the exact tools and techniques so they can be replicated or enhanced by others. “In field biology, we typically observe with our eyes, but our observational capability is vastly limited compared to what machines can accomplish.”
Similar to security personnel entering a high-security building, the bees “buzz” into their hive, presenting the QR code on their backs. While they have unrestricted entry, they are monitored through an automated imaging system specifically designed to track their movement through a customized entrance equipped with a camera sensor. The QR codes attached to the bees are known as fiduciary tags, which contain minimal identification details and can be quickly recognized and recorded by the imaging system, even in poor visibility. This system represents a departure from traditional entomological methods, which rely on visual monitoring of bees over short periods, enabling much more extensive and thorough observations.
Challenges for Organic Beekeeping
Organic beekeeping generally entails maintaining hives without chemical pesticides, herbicides, or synthetic substances, and placing them away from polluted areas. Although the U.S. Department of Agriculture’s National Organic Standards Board proposed specific criteria for certifying honey and other beekeeping products as “organic” in 2010, these standards were never finalized. Honey bees can fly considerable distances—up to around 10 kilometers—when necessary, but the researchers hypothesized that such long flights are rare and that bees typically forage much closer to their hives, possibly less than one kilometer, according to López-Uribe. This finding implies that the recommended forage and surveillance zones for organic beekeeping may be unnecessarily large.
With a more precise understanding of bee foraging behavior, this situation may change, the researchers suggested. Honey bees communicate the locations of food resources to their hive mates through a movement called the “waggle dance.” López-Uribe noted that researchers spend considerable time studying and decoding these dances to gauge the distances traveled by bees from their colonies, a process that could be significantly enhanced by accurately monitoring how long individual bees spend foraging.
“The waggle dance provides the best insight into bee foraging behavior, but it’s derived from human observations that consist of a limited number of hours over a couple of weeks. Thus, we approached the electrical engineering team to explore technological solutions for better observation,” López-Uribe shared. “Our goal is to verify if the estimate of 10 kilometers is biologically correct. Can we pinpoint exactly how far honey bees travel from their hives?”
Collaborating for the Bees
The entomologists sought assistance from Julio Urbina, an electrical engineering professor and co-corresponding author of the study, who brought Diego Penaloza-Aponte, a doctoral student in electrical engineering, into the project.
“There wasn’t any technology like this available previously,” Urbina stated. “This paper represents a significant first step, paving the way for future opportunities—largely due to the enhanced collaboration between our teams.”
The researchers emphasized that this collaboration was not a case of separate contributions from biologists and engineers. Instead, the team’s members immersed themselves in each other’s fields to better appreciate their distinct needs and constraints. While electrical engineers gained hands-on experience in handling and observing bees, entomologists visited labs to understand the design and construction considerations for automated technologies.
“Previous systems designed to monitor bees were developed for use in controlled laboratory settings,” Penaloza-Aponte remarked. “Our aim was to create a system that could function in rural areas, away from lab settings, powered by solar energy, and to ensure the technology is open source, allowing anyone to utilize and modify it.”
Penaloza-Aponte further noted that accessibility was a priority. The entire setup costs less than $1,500 per apiary for six colonies, and all components are commercially available.
Gaining Insights
For their study, the researchers used AprilTags, small QR codes smaller than a pinky nail, which they attached to worker bees without hindering their movement or causing harm. Throughout the spring and summer seasons, the team tagged 600 young bees biweekly, monitoring six colonies. In total, they tagged more than 32,000 bees across six apiaries.
“We focused on young bees to better track their aging process, especially when they begin flying and when they stop,” said Robyn Underwood, a Penn State Extension educator in apiculture and co-author of the paper. She added that younger bees are also more pliable and do not sting, making them easier to manage. “Once the bee was mature enough to fly, it would exit the colony, and the camera would capture it. Our sensor would read the QR code in real-time, logging the bee’s ID, date, time, direction (leaving or entering the hive), and the ambient temperature. This way, we could follow individual bees throughout the season. When did she leave? When did she return? What was her activity?”
The findings revealed that most foraging trips typically lasted one to four minutes, possibly for weather-checking or to defecate outside the hive. Longer excursions generally lasted no more than 20 minutes, but 34% of the tagged bees were observed to be out for over two hours. This could indicate an extended foraging session, a bee that failed to return, or unrecorded activity if the bee re-entered upside down. During certain weeks with fewer flowers, more bees were observed spending additional time foraging, suggesting they had to travel further to find sufficient food.
“We also discovered that bees forage for a significantly longer period throughout their lifespans than previously understood,” Underwood noted, explaining that honey bees are thought to live around 28 days. “Our observations show that bees forage for up to six weeks, and they usually start foraging two weeks after they mature, meaning they tend to live longer than we had initially believed.”
The cameras monitoring each hive operated continuously, connected to a microcomputer, with researchers retrieving the data during weekly visits.
The team encountered an anticipated challenge early in the project—bees lingering at the hive entrance. The camera sensors identified individual QR codes repeatedly throughout the day.
“It turns out some bees prefer to hang around at the entrance, and the camera will read them each time they pass by,” Diego explained. “This is why the programming is advantageous. It can filter out that excess data and ensure we are tracking what’s genuinely significant.”
Future Developments
The researchers are currently collaborating with a team from Virginia Tech to evaluate how foraging durations correspond with decoded waggle dances. Moving forward, they aim to tag and monitor different bee species as well as other types of honey bees, including drone and queen bees, to explore various aspects of the colony’s dynamics. They also plan to host workshops for both scientists and beekeepers on how to build and implement their monitoring systems.
Other co-authors of this study include Sarabeth Brandt, a doctoral student in electrical engineering, and Selina Bruckner, a postdoctoral researcher in entomology at Penn State; Erin Dent, an undergraduate student at Texas A&M University who participated in the project as a Project Drawdown scholar in summer 2023; and Benedict DeMoras from the Department of Entomology at Cornell University. Additionally, this team is collaborating with Margaret Couvillon and Lindsay Johnson from the Department of Entomology at Virginia Tech, and Scott McArt from the Department of Entomology at Cornell University.
This research was funded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture.
