A blind man is walking down the street, accompanied by his guide dog. Approaching a busy junction, the animal leaps into a torrent of traffic, dragging its owner behind him. The screeching of tires and car horns is ear-splitting, as motorists desperately try to avoid running them down.

The pair eventually reach the other side of the street. After a few seconds, the man takes a biscuit from his pocket and offers it to the dog.

A passer-by who had observed the incident is amazed: “Why are you rewarding your dog with a biscuit? He nearly killed you!”

The blind man grimaces and replies, “I'm trying to find out where the mutt's head is, so I can give him a good kick up his rear end.”