Various people passed by: a tired businessman with a small suitcase, two chatty girls in tracksuits, an elderly couple. Bim paid no attention to any of them.

But when a young family approached — mother, father, and their about five-year-old daughter holding a large teddy bear — Bim suddenly tensed. He froze, pinned back his ears, then suddenly lunged forward and started barking loudly at the girl, circling around her and sniffing the teddy bear.