Every so often, if you ride Moscow's crowded subways, you notice that the commuters around you include a dog - a stray dog, on its own, just using the handy underground Metro to beat the traffic and get from A to B.
Yes, some of Moscow's stray dogs have figured out how to use the city's immense and complex subway system, getting on and off at their regular stops.
Russia: Stray Dogs Master Complex Moscow Subway System - ABC News