My mom has two sweet terriers, half westie and half yorkie, a pair of brothers names Jack and Luke. They are great people dogs, but one of them has a very high prey drive and cannot be walked off a leash or let loose near our chickens. He sits twitching and shaking just watching our chickens, you can tell he really wants to chase them. They can be a little loud when they alert to strangers, but calm down fast, and are very protective of my daughter. They are tenacious, smart and funny little dogs!