Colin showed me this link last night:
I was amazed by the mother squirrel's act. From a dog lover's point of view, in the first picture, it didn't look like the dog is going to harm the baby squirrel, he maybe want a game with the baby squirrel but for non doggie lovers, they think a dog chasing a squirrel is cruel.
All my shelties chase squirrels and I know they never going to get them, is just like in the wild, some animals chase another animals, is a circulation. You don't expect to see a mice chase a cat, do you?