The ability to recognize oneself in the mirror is not a universal skill across different species. Most animals treat mirror images as if they were looking at an animal through a window. But chimps can recognize themselves, as demonstrated in a remarkable study by Donald Griffin. He allowed chimps to become familiar with their mirror images, then gave them an anesthetic to put them to sleep for a few minutes, and painted a red dot on their forehead while they were under. After awaking, they showed no indication of being aware of the red dot on their forehead until they looked at themselves in the mirror. Chimps then touched their own forehead, not the one of the chimpanzee visible in the mirror! Watching Viki, it is difficult to see why she would be doing the things she is without understanding she is looking at herself.