Current Sensing Components and Sensor-Vendor Lists

Temperature sensors, i.e. thermometers, provide information on several important conditions, namely state of the brood, details of the winter cluster, and internal and external environmental conditions.

The presence of brood in the hive is a critical indicator of colony health, and a thermometer in the brood box can indicate the presence of brood, or at least, the presence of brood near the sensor. More temperature sensors will provide more detail. As is well known, bees maintain a brood temperature of 34^oC or 94^oF, with very little variation. In winter, bees cluster to maintain colony warmth, and temperature sensors in each box will reveal the location and size of the winter cluster. Cluster location and weight, taken together, can indicate the need for additional feed.

Finally, temperature sensors in the hive, but not embedded in the brood or the winter cluster, indicate in-hive conditions. With optimal in-hive conditions (temperature, humidity, oxygen level, etc.), bees need not expend excess energy when performing their tasks, which could result in less stress, better health, and more production.

Most all of the sensor sets monitoring in-hive temperature also monitor in-hive humidity.

Electronic Temperature & Humidity Sensor Vendors/Organizations
Company	Product
Aisne, France	B-Keep
ApisProtect, Ireland	ApisProtect
Arnia, England	Arnia
Beehive Monitoring, Slovakia	Beehive Monitoring
BeeMonitor, Wales	BeeMonitor
BeeWise, France,	BeeWise
BroodMinder, USA	Broodminder
BuzzTech, New Zealand	Hive Heartbeat
Hivemind, New Zealand	Hive Heartbeat
Hivetool, USA	DIY
Modusense, New Zealand	Modusense
Nectar, Canada	BeeCon
OSBeehives, USA	BuzzBox
Pollenity, Bulgaria	BeeBot
Save-bees, Greece	Save-bees
Solutionbee, USA	B-ware
The BEEP Foundation, Netherlands	B-ware
Wolf-Hive Scale, Germany	Hive Scale

Temperature References

Graham, J. Ed. (2015). The Hive and the Honey Bee. Pages 177, 291-292, 652.

Before opening a hive, experienced beekeepers can discern a lot of information about the state of the colony by observing the activity at the front of a hive and on the landing board. The book, At the Hive Entrance, provides many examples of what we can learn by examining the hive entrance for clues about the health and productivity of the colony inside. We cannot be in the bee yard all the time, however, so the possibilities of an automated entrance monitoring system are enticing. The book, At the Hive Entrance, originally in German, tells you, “How to know what happens inside the hive by observation on the outside”.

Observable landing board activity includes:

• Forager departures and returns
• Pollen collection
• Predators: hornets, skunks, birds, mice,
• Worker orienting, queen mating, drone activity
• Colony activities: fanning, guarding, bearding, cleansing, swarming, absconding, usurping, robbing, undertaking…
• Unexplained rapid colony loss

Landing board activity monitors can be grouped by the type of sensor and the variety of activities they can (potentially) monitor. The most broadly capable activity monitors are video-based. There is, however, only one of these on the market, Keltronix’ EyesOnHives, and at the moment (2019) it can only monitor the general level of activity at the hive entrance. The second type of entrance activity monitor is audio-based. These are not to be confused with in-hive audio-based monitors. An audio-based entrance activity monitor is available from Arnia. The third type of entrance activity monitor focuses mainly on foraging; it counts the bees entering and exiting the hive. Most bee counters somewhat impede other entrance board activities so their use is limited. Both commercial and do-it-yourself bee counters are available.

• Video-based Activity Monitors

Using video to monitor a hive entrance enables various activities to be recorded such as foraging, drone activity, mating flights, swarming, robbing, absconding, undertaking, and predation by wasps, birds, skunks, and others. Also, capturing video of the hive entrance together with image interpretation software to count bees offers a less-intrusive means of counting foragers. Video-based bee counters overcome the disadvantages of motion-based bee counters which reduce the hive entrance and can interfere with cleaning activities, temperature control, etc. As bees tend to die outside the hive, an excess of departures over arrivals may indicate the presence of other problems.

• Keltronix’ EyesOnHives

Keltronix’ EyesOnHives appears to be the first commercially available system that captures video imagery of activity at the hive entrance, analyzes the video automatically, and reports the results on a website where it is accessed by the beekeeper. The software analyzes flight activity levels rather than counts of forager flights in and out, but this is enough to tell when foragers are flying, how many (in terms of bees/second) are flying, when swarms or orientation flights are taking place, and to distinguish between swarms and orientation flights. Each time there is a significant change in activity, the system records a few seconds of video for the beekeeper to review later. The system also records a time-lapse video of the entire day’s activity.

Video cameras consume significant power, and this system needs a connection to household current, which limits its use to yards with an electrical outlet. Information is transferred from the system to the internet by Wi-Fi, so the yard must also have Wi-Fi access. Users buy the camera system and subscribe to the data analytics service.

EyesOnHives: A video-based hive entrance monitoring system, by Keltronix 

• Audio-based Activity Monitors

Audio-based entrance activity monitors consume much less power than video-based monitors and can run on small batteries. Like video data, audio data can be interpreted by software to provide beekeepers with reports regarding the status of their colonies. Specifically, the pitch or frequency of bees’ buzzing indicates that bees are either flying or fanning, and the loudness or intensity at these frequencies indicates, roughly, the number of bees engaged in that activity. Besides foraging, other activities cause bees to leave the hive in great numbers, activities such as orientation flights, swarms, absconding, queen mating flights, etc., and these may also be detected by audio-based entrance activity monitors.

• Arnia’s System

Arnia’s audio-based entrance activity monitor is embedded in the small box that contains a processor and transmitter for other sensors. This box is placed at the hive entrance where the microphone can capture landing board activity. The audio activity is analyzed automatically, and sent to the Arnia website where it is accessed by the beekeeper. The software analyzes activity levels rather than counts of forager flights in and out, but this is enough to tell when foragers are flying and to detect periods of heightened activity, such as when swarms or orientation flights are taking place.

The chart below, from Arnia, shows flight and fanning noise at the hive entrance for a two-day period; flight noise in yellow and fanning noise in purple. The fanning noise, with peaks before 6 am and 6 pm is similar both days, while the flight/foraging pattern has a single peak on the first day and a double peak on the second day.

Flight and fanning noise at the hive entrance for a two-day period as captured and displayed by Arnia’s system.

• Bee Counters

Foragers bring the colony the nectar and pollen it needs, and the third type of entrance activity monitor focuses mainly on foraging, counting bees exiting and entering the hive. These bee counters use mechanical, optical, or electrical field sensors to detect the passage of bees in and out of the hive through small holes which impede other entrance board activities (such as fanning and undertaking), limiting their use to brief periods of time. Both commercial and do-it-yourself bee counters are available.

Yet another type of bee counter, using radar, may be on the market in late 2019 or 2020. A prototype of the product was field tested in 2018. Papers describing the research are listed at the end of this section.

• Commercial bee counters

Lowland Electronics
The Lowland Electronics bee counter has been available for many years.

• Do-it-yourself bee counters

HiveTool.org
HiveTool.org is a site that helps technically-savvy users build their own colony monitoring equipment using open-source software and off-the-shelf hardware components such as Raspberry Pi and Arduino. One of the tools offered is a video-based bee counter. The HiveTool website is run by Paul Vonk, winner of the 2015 Bayer Crop Science Bee Care Community Leadership Award for his work on colony monitoring.

Hydronics Honey Bee Counter
Hydronics (aka Tom Hudson  has developed two bee counters. They are posted on Instructables.
Tom’s original BeeCounter is here.
His second, more advanced one is here.

Electronic Landing Board Activity Sensor Vendors/Organizations
Company	Product
Arnia, England	Arnia
Beehive Monitoring, Slovakia	Beehive Monitoring
Hivemind, New Zealand	Hivemind
Hivetool, USA	DIY
Hydronics, USA	DIY
Keltronix, USA	EyesOnHives
Lowland Electronics, Belgium	BeeSCAN, ApiSCAN
Melixa, Italy	Melixa

• Raspberry Pi Bee Counter
  A bee counter project using the Raspberry Pi computer can be found here.

• Toward a more-accurate video-based bee counter

It is not that difficult to point a video camera at a hive entrance and stream the view to the internet. In contrast, automating the analysis of that video stream to draw meaning from it is a difficult task.

Research on video-based bee counters itemizes some things that cause difficulty in processing the video stream: the changes in natural light as the day progresses, the speed of flying bees, the tendency of bees to cluster at the entrance and to walk atop one another, the similarity of bees to each other and to their shadows, and so on.

It seems plausible that a video-based bee-counter could be created by providing a view of the hive entrance that mitigates the difficulties that video analysis encounters. For example, the design might make the bees walk through a transparent ‘tunnel’ a few inches long and the width of the hive entrance. The tunnel could be illuminated with natural light filtering through a translucent cone or box above it to minimize variation in illumination. The ceiling of the tunnel could be low enough that only one bee could be in one spot at a time (i.e., not one on the floor and one above it on the tunnel’s ceiling) so that bee images do not overlap, and the bees’ shadows are under the bees where they will not confuse the bee counter. The tunnel would make the bees walk, not fly, so a slower frame rate could be used.

The resolution of the image should be sufficient to distinguish which end of the bee is which, distinguish between workers and drones, and to identify pollen bearers. Such a system would get bonus points for detecting drones and queens. Ideally the analysis software would also detect SHB adults and larvae, wax moths, etc., and it would be fantastic if it could detect Varroa mites riding on bees.

• Research on Entrance Activity Monitoring

Monitoring hive entrance activity is an active area of research. Here are just two examples:

• Pollen Bearing Honey Bee Detection in Hive Entrance Video Recorded By Remote Embedded System for Pollination Monitoring.

• A Computer Vision Algorithm for Omnidirectional Bee Counting at Langstroth Beehive Entrances
• Arnia has successfully developed a means to remotely detect, alert and locate an Asian Hornet attack on a bee hive.

Research on using radar to count forager activity:

• An index for assessing the foraging activities of honeybees with a Doppler sensor.

• The radar microphone: A new way of monitoring honey bee sounds.

Accelerometers are simple and cheap, and they can inform the beekeeper that a hive has been tipped over by storms, bears, vandals, or other causes, as well as sending a message when a hive is moved, which may be important if the move is unexpected. Finally, precise hive location is an important data item in colony management software.

Motion Detection Vendors/Organizations
Company	Product
ApisProtect, Ireland	ApisProtect
Arnia, England	Arnia

 

Not only can a GPS system sense hive movement, but also it can report the location of the hive. This is an especially important anti-theft functionality. Knowing hives’ locations is also helpful when visiting them, whether for inspections or for collecting them after a nectar flow or pollination event.

GPS Hive Location Vendors/Organizations
Company	Product
Aisne, France	B-Keep
Bee Label, France	Connected Beehive
Beewatch	BeeWatch Scales
BeeWise, France	BeeWise
European Beekeeping Company, Cyprus	ApiSafe
Hivemind, New Zealand	Hivemind
Melixa, Italy	Melixa
Modusense, New Zealand	Modusense
MyApiary, New Zealand	Trusted
Nectar, Canada	BeeCon
OSBeehives, USA	BuzzBox
Save-bees, Greece	Save-bees
Swienty, Denmark	Beehive Scale XLOG

A recent addition to the colony monitoring sensor set is the infra-red camera. These usually combine the images from both a standard digital camera and an infra-red camera so that the heat sources seen in the infra-red image appear within the standard image, which is usually depicted in outline. The uses of infra-red camera in beekeeping are still being discovered, but typically they are used to find the location of the winter cluster in the hive and to find the precise location of a colony when removing a colony from a building.

The only monitoring technology organization offering an infra-red camera is the Danish company BeeWatch.

Several beekeepers recommend the FLIR ONE PRO.

As the uses for infra-red cameras are still being explored, the latest information on their use and value can be found in beekeeping magazines.

Bee researcher Jerry Bromenshenk has written an excellent series on the use of infra-red photography by beekeepers for Bee Culture magazine.

• Infrared: The Next Generation in Colony Management
• Should An Infrared Camera Be in Your Toolkit?
• Professional IR Cameras

Beekeeper Wyatt Mangum has also written extensively on the utility of infra-red or ‘thermal’ cameras in beekeeping.

• Unusual Thermal Images of A Winter Cluster: 
• What’s Hot: 
• Unusual Winter Cluster Behavior: Finally Observed With Thermal Imaging: 
• Hot Mice! in The Hive: 

Figure 1 - Colony is clustered in the top medium boxes. The brood box, almost invisible, is vacant. Hive entrance is to the left.

Figure 2 - Colony is clustered in the brood box. Hive entrance is facing the camera.

 

Everyone knows that bees buzz. Not everyone knows that bees’ buzz carries meaning. Experienced beekeepers, though, can tell something about the state of a colony by listening carefully as they approach the hive. Some colony monitoring systems include acoustical sensors. Other systems use smartphones as their technology platform and require the user to place the phone at the hive entrance briefly to collect an audio sample.

A number of capabilities have been claimed for these systems. Potential users should keep in mind that this technology shows promise, but is in its infancy, and the same hive state, such as queenlessness, may sound quite different in different colonies. 
“>BeeBot

Colony Acoustical Activity Sensor Vendors/Organizations
Company	Product
ApisProtect, Ireland	ApisProtect
Arnia, England	Arnia
BuzzTech, New Zealand	Hive Heartbeat
Hydronics, USA	DIY Apidictor
Nectar, Canada	BeeCon
OSBeehives, USA	BuzzBox
Pollenity, Bulgaria	BeeBot
The BEEP Foundation, Netherlands	BeeBot

Smartphone-based acoustical sensors include:

• Apivox Smart Monitor
• Oharkovi acoustic bee hive analyzer
• Bee Health Guru
• Beegnostic

Besides acoustical signals, some research is also being done to detect and interpret hive and comb vibration, primarily by Martin Bencsik:

• Honey Bee Vibration Monitoring Using the 805M1 Accelerometer
• Extensive Vibrational Characterization and Long-Term Monitoring of Honeybee Dorso-Ventral Abdominal Vibration signals

 Acoustics reference list.

• Bromenshenk. A New App Listens to the Problems of Bees.
• Evans. Remote Hive Monitoring.
• Atauri. Platform for bee-hives monitoring based on sound analysis.
• Ahmad. Remote Beehive Monitoring Using Acoustic Signals.
• Kulyukin. Toward Audio Beehive Monitoring: Deep Learning vs. Standard Machine Learning in Classifying Beehive Audio Samples.

Colony Acoustics Patents
Patents have been granted to those who interpret bee buzzing:

• To measure the degree of mite infection: System for monitoring hive health
• To monitor colony activity: Acoustic sensor for beehive monitoring
• To detect the presence of Africanized bees: Method and device for identifying different species of honeybees

Free acoustics interpretation software
Try it yourself. Free software for acoustic analysis includes:

• Cornell Ornithology Lab’s Raven.
• Audacity.

The story of the original apidictor can be found here: Listen to the Bees by Rex Boys/Eddie Woods

How well we know that the weather influences bees’ activities. Whether it is plants’ production of nectar and pollen affecting forage for those products, excess heat driving the foraging of water collectors, or cold air or strong winds discouraging all flight activity, the weather outside the hive can explain a lot of in-hive activity.

Many vendors of colony monitoring systems also place temperature sensors outside the hive too, often in conjunction with the hive scale. Many of these external sensor sets include a humidity sensor as well, and some even include a rain gauge. Still other vendors take the approach of incorporating data from a nearby weather station into the data display.

Weather Sensing Vendors/Organizations
Company	Product
Arnia, England	Arnia
Bee Label, France	Connected Beehive
BeeMonitor, Wales	BeeMonitor
Beewatch, Denmark	BeeWatch Scales
BroodMinder, USA	Broodminder
Hivemind, New Zealand	Hivemind
Hivetool, USA	DIY
Melixa, Italy	Melixa
O’Keefe Electronics, USA	Wi-Fi Hive Scale
Optibee, France	Optibee
Save-bees, Greece	Save-bees
Solutionbee, USA	B-ware
Swienty, Denmark	Beehive Scale XLOG
Wolf-Hive Scale, Germany	Hive Scale

Weather references

Figure 2.14, Three-year record of weekly weighings of a honey bee colony… The colony gained weight… for just a few weeks each summer and then gradually lost approximately 25 kg of weight over the winter period, October to May. T. D. Seeley. (1995) The Wisdom of the Hive. Page 44.