Westie discovers squirrels

We were out in the back yard this afternoon when out of the blue Zach took off running. In a fenced yard I was not concerned he would go far, but curious what he saw. Next I saw a squirrel running as fast as it could up the tree. I was in amazement as Zachary went away from the tree just far enough that the squirrel felt it was safe to come down, then he treed the poor squirrel again. After about twenty minutes I brought Zach inside so the squirrel could continue his journey. I knew it was only a matter of time, since our former Westie loved to chase squirrels. Actually, all the Westies that I have ever known love to chase squirrels.