Poor Sailor has been trained not to be himself. He has been trained to control his Dog Nature. He won't bark, nor make a sound, or jump off and go after the squirrel.
Ben informed me that Sailor will not cave in to his dog nature. He watched closely every time a squirrel came for a peanut. He watched the squirrels fight their territorial rights and who should have the next peanut.
I admire his trainer and I admire Sailor's willing to submit and just be a humble dog. But I also feel sorry for him that he can't just be a dog doing dog things like chasing squirrels. But then he is also a much beloved dog who admires his owners, those who have trained him.