This breed has a strong working instinct gained from both its parents, resulting in a dog that needs not only physical exercise but mental stimulation too. (animalso.com)
A dog with good working instincts will circle the small flock and hold them together. (canismajor.com)
Puppies born with physical faults that disqualify them from showing or competing (wrong color or markings, structure not conducive to work, working instinct lacking) were killed because there was nowhere else to put those dogs. (ilrdb.com)