Symmetrical Dogs

The thing about having two pit bulls is that (when they are not running at top speed through the house, destroying everything in their wake) they sometimes do adorably symmetrical things.

Norman and Harry Potter can even be used to teach the three types of symmetry. There's reflection symmetry:

Rotational symmetry:

And a whole heck of a lot of translation symmetry:

Symmetrical dogs: a perfectly legitimate argument for fostering a pit bull.