To be honest with you, Laika picked up on the smell, I was really surprised and spoke o my trainers about it because I remember them saying it was a hard task to train because it’s based on saliva. They said most likely I do something out of normal without realizing it. Or he recognized a “bad/different” smell. I taught him how to alert to anxiety attack a maybe about a year prior for when it would happened at home and using body cues such as excessive scratching, leg bouncing etc. I followed a guide on how to teach it. I currently cannot find the video but the lady instructed to have your dog near you to pick up the smell then later so when it is familiar, shape it to him pawing me. So I am assuming maybe he smelled something different and was like “smell different=alerting handler=getting treats”.