Wolves Demonstrate Self-Awareness in Sniff Test

Grey wolves pass an olfactory version of the mirror test for self-recognition. Since the 1970s, scientists have employed the mirror test as an assay of self-awareness. If an animal or child recognizes themselves in a mirror — for instance, touching a mark placed on their body by the experimenter while inspecting their reflection — they are said to possess self-awareness. The evidence from great apes is the most compelling, though elephants, dolphins, certain species of birds, and even some fish have showed some signs of self-recognition in the mirror test. However, it is still unclear if failure to recognize oneself in a mirror confirms that an animal lacks self-awareness. The mirror test is biased toward those species that use vision as their primary sense and possess limbs capable of pointing to parts of their bodies. How could other species demonstrate that they know the difference between self and other?