paranoid behavior in our 11 month old Morkie

Question
every once in a while our dog will stand on alert and track things that we do not see. she never is aggressive when this happens just odd acting. It's like she is watching something run back and forth but there is nothing there.

Answer
This might be low level temporal lobe seizures, a response to floaters in the eye or developing eye problems, or it might just be that your dog is 'tracking' dust in the air.  Observe her more closely to see how many times a day/week this occurs and if any other odd visually related behaviors might occur that you are missing.  If you observe multiple events and other behaviors, take the dog to the veterinarian and report this behavior.