How do dogs invite play?:
Most mammals stop playing as they reach adulthood, but not dogs! But
one of the problems dogs face is how to communicate that they want to
play. Much play involves mock fighting and fleeing, so it is important
to say that a particular action is only in fun.
The most popular signal for play is the "play-bow", in which the dog
lowers its front half, while keeping its rear end high in the air.
The dog keeps its front legs in a "sitting sphinx" position and its chest
touches the ground. The hind legs stay straight with the paws on
the ground. And the
dog looks intently at its companion and makes little forward movements
as if to say "let's go!"
Because the play has been initiated by the special signal, the playing
dogs will not start attacking each other. They may change roles of
chaser and escaper several times during the play bout, running around
in wide circles, having a fun time.
Another signal for play is the "play-face", an expression that is
the equivalent of the human smile. The dog pulls its lips back
horizontally (not vertically, so the teeth are not shown). Other
signals include nudging and pawing. Dogs may also offer something
to get play started. The dog will bring over a stick or a ball,
for example, face its companion, and put the object on the ground
between its front feet. The minute you reach for the object, the
dog grabs it and zips off, wanting you to begin the chase.
For dogs to play well as adults, they must learn correct play
etiquette as puppies. Little puppies learn not to bite too hard
when they play. If a dog grows up without its littermates, it may
not learn this "soft-bite". When it plays as an adult, it may
bite too hard, and real fighting could occur.
Source: Illustrated Dogwatching, by
Desmond Morris, Crescent Books, New York, 1996, pp. 55-56.