Master with behavior problems? Too bossy? Thinks he owns the house? Not enough treats? Ask Dr. MacGregor and master your master's will !
Our Westie is 3 1/2 years old and with in the last year he has for no reason occasionally starts growling at our feet and then biting them.
Just ignore it. Many Westies do this and behaviours that you don't want to see repeated/increased should just be ignored.