Blue Heelers have to be one of the best and smartest dogs in the world. Originially meant to be a cattle dog, they can be trained to be whatever you want them to be. They are very fast learners and are very loving and loyal. They have almost no aggression too. I have one thats about 4 months old and i can stick my hand in front of his mouth while he is eating and he doesnt even try to nip or growl or anything. They are great pets i would recommend them to anyone. I will always have a blue heeler.