A new study has found that honeybees can recognize human faces in photographs and remember them for at least two days. This discovery could aid in the development of better facial recognition software through the study of insect brains. 
Many researchers still believe that recognizing human faces requires a large brain and a specialized area dedicated to processing facial information. However, the results from this bee species have upended that notion, according to lead researcher Adrian G. Dyer from Johannes Gutenberg University, Germany.
Dyer stated that, to his knowledge, this is the first time a non-vertebrate species has been found capable of recognizing the faces of other species. However, not all bees can accomplish this; some confuse faces, although this is more due to a lack of experience than poor recognition ability. Meanwhile, some humans struggle to recognize others’ faces, a condition known as prosopagnosia.
In the study involving bees, Dyer and two colleagues showed honeybees images of different human faces. The photographs had similar lighting, background, and size, featuring only the face and neck to prevent the insects from assessing clothing. Some individuals even had similar facial features.
The researchers attempted to train the bees to recognize the photo of a specific man by placing a drop of sugar next to it. Other images were paired with a bitter drop.
Some bees clearly did not realize they needed to pay attention to the image. However, five bees learned to fly towards the picture along the horizon so they could see it clearly, Dyer noted. In fact, these bees would often hover a few centimeters in front of the image for a while before deciding where to land.
The bees learned to distinguish faces with over 80% accuracy, even when the faces were somewhat similar, regardless of where the photo was placed. Additionally, like humans, bees performed worse when the image was presented upside down.
“This is evidence that recognizing faces does not require a specialized brain area or an advanced nervous system“, the researchers concluded.
Moreover, two bees tested two days after the initial training retained information in long-term memory. One bee achieved 94% accuracy on the first day and 79% two days later, while the second bee dropped from 87% to 76% over the same timeframe.
Dyer explained that the bee colony likely doesn’t comprehend what a human face is. For them, it’s merely spatial patterns or unusual flowers. Bees are renowned for their ability to recognize patterns to differentiate flowers. As a highly social species, they can also distinguish between their fellow bees. However, this new study has shown that they can recognize human faces better than some people, despite having only 1/10,000th the number of brain cells.
The findings could help researchers develop facial recognition technology in airports and public places. Dyer believes that if bees can learn to recognize human faces in photographs, they can also recognize real human faces.
