Every dog owner will be familiar with the puppy eyes given at mealtimes. Whether it's a juicy piece of steak or a slice of cheese, nothing escapes their nose. But if they lick their lips it could be ...

When the Nobel Prize-winning ethologist Konrad Lorenz forced a dog to lie flat on the floor in a submissive position, the dog stopped struggling, went slack, and then flicked its tongue as if it was ...