Unlike some dog breeds, males and females make equally good pets. The main difference is that males tend to have more impressive coats, and unspayed females will 'blow' coat after every heat cycle. Males should appear masculine, females feminine. 

The herding instinct is still strong in many Shelties. They love to chase things, including squirrels, ducks, and children. When people are milling around the yard, Shelties sometimes try to "herd" the people into a group by running around, barking, and nipping at heels. This tendency appears most when children run around the yard in a group.  Shelties love to run in wide-open areas. The space should be safe and they should not get too far away.  Shelties usually love to play.  They do best with a sensitive, yet firm, owner. 

The Sheltie is, above all, an intelligent herder and likes to be kept busy, although their activity level usually coincides with their owner's level.  Shelties also are very smart, making them highly trainable and wonderful companions.