The dog wags its tail only at living things.
A tail wag, the equivalent of a human smile,
is bestowed upon people, dogs, cats, squirrels,
even mice and butterflies. - but no lifeless
things. A dog won't wag its tail to its dinner
or to a bed, card, stick, or even a bone.
How to Talk to Your Animals (ed. Open Road Media, 2011) - ISBN: 9781453223413