Very VERY smart! They can figure their way out of anything. Say you set up a gate to block off an area of your house... oh you can bet they will figure their way around it in five minutes!

They are also VERY loyal and are always by your side. If you don't want a dog that will get underfoot, then you don't want an Aussie. I can't even go to the bathroom without them following me and laying outside the door, their noses pressed up against the crack sniffing to make sure I'm actually still there.