A red ant is put on the surface of a mirror. The ant studies its reflection: moves its head, tries to feel the image with its antennae and mandibles.
If an ant is put instead on the surface of plain glass with similar ants on the other side, it doesn't behave like that. But if it receives a dot of blue paint on its "forehead" and then put on a mirror, it will clean the paint off upon seeing it. It won't do that before it is put on a mirror. If the dot is on the back of its head and cannot be seen in the reflection, it won't either. If the dot is brown, and cannot be seen on the background of the ant's head, the ant still won't clean it off.
A mark on the head is the standard test for self-recognition in a mirror. A creature that understands that it is seeing its own reflection will normally try to investigate the mark or remove it once it sees it in the mirror. Until now, this ability was shown (besides humans) in apes, dolphins, magpies and elephants.
And now, it appears, in red ants.
Seems like this nontrivial task doesn't require very many neurons!
Link to the article: http://www.journalofscience.net/File_Folder/521-532(jos).pdf
