A man has a dog called Mace, which he keeps in the house  all the time, because all it does is eat grass. He also has  a favourite tool, his wrench, which he uses all the time.

One day He looses the wrench. He looks every where for it  but can't find it. The dog gets out, eats all his grass and  there in the middle of the lawn is his wrench.

The man starts singing "A grazing Mace how sweat the hound, that saved a wrench for me".