Honeybees may look pretty much all alike to us. But it seems we may not look all alike to them. A study has found that they
can learn to recognize human faces in photos, and remember them for at least two days.

The findings toss new uncertainty into a long-studied question that
some scientists considered largely settled, the researchers say: how
humans themselves recognize faces.
The results also may help lead to better face-recognition software, developed through study of the insect brain, the
scientists added.

Many researchers traditionally believed facial recognition required a
large brain, and possibly a specialized area of that organ dedicated to
processing face information. The bee finding casts doubt on that, said
Adrian G. Dyer, the lead researcher in the study.

He recalls that when he made the discovery, it startled him so much
that he called out to a colleague, telling her to come quickly because
“no one’s going to believe it—and bring a camera!”

Dyer said that to his knowledge, the finding is the first time an
invertebrate has shown ability to recognize faces of other species. But
not all bees were up to the task: some flunked it, he said, although
this seemed due more to a failure to grasp how the experiment worked
than to poor facial recognition specifically.

In any cases, some humans also can’t recognize faces, Dyer noted; the condition is called prosopagnosia.

In the bee study, reported in the Dec. 15 issue of the Journal of Experimental
Dyer and two colleagues presented honeybees with photos of human faces
taken from a standard human psychology test. The photos had similar
lighting, background colors and sizes and included only the face and
neck to avoid having the insects make judgments based on the clothing.
In some cases, the people in the pictures themselves looked similar.

More here.