Had 2 Jack Russel's, they are really good small dogs. They CAN be high strung at times but most of the time they just chill. They are easy to train and are great companions. Our first one was great for security, he was very smart and it was like he had a 6th sense when it came to strangers. The second one we got from a shelter and was beat so he is mostly scared of strangers, he might look out the window and bark a few times to let you know someone or something is outside but if someone comes in he usually retreats to another room. The short haired Jack Russel's don't shed much either but they do like alot of attention.