I was waiting for the subway in Union Station and noticed several people watching a scene on the train platform. In a small area under one of the escalators, there were two men, one in police uniform, interacting with a sniffer dog (a dog trained to detect hidden contraband).
I decided to position myself to get a better view.
Luggage of various sizes was strewn about the contained area. The plainly clothed man slowly walked the dog on a leash, taking him in front of each piece of luggage. When the dog correctly stopped and pawed at a certain piece of luggage, both men would praise and pet the dog, sometimes giving the dog a treat.
This reinforcement phase would result in apparent great joy not just to the dog but to the men also! The dog would yelp a little, sometimes raise up on hind legs as if to dance, and the men would smile or laugh and continue to offer statements of praise.
This training was repeated several times while I was there. After a successful trial, one of the men would move the luggage to an area where the dog couldn't see him. Then he would put the contraband inside a different piece of luggage and then would carry the various pieces of luggage back to the spot under the escalator, and place them randomly for a new trial.
Most people were smiling as they watched the action. Some, like me, were fully engrossed.
During a break between trials, I approached the man who stood waiting with the dog while the other man was moving the contraband to another piece of luggage. "Are you training a new dog?"
"No – this dog is great and has done this work for a long time. We are just reminding him of the job, doing some scheduled re-training."
"So this is a booster session?"
"Yup, this is a booster." He was smiling, probably was used to a curious public.
Usually I hardly notice who is on the platform with me while I wait for a train to arrive. It was nice to be part of a small community engaged in such a joyous, if not quirky, scene for a short while.