nipping

Question
we have a loverly 1 yr old Aussie - Max.  Sometimes when he's around kids (ours and others)and the kids are loud, playing rough with each other or running past, he will nip at the back of their legs. As a puppy he hearded our family alot and left holes in all our pant legs, but that has stopped.  The nips dont seem to be out of anger, more like over excited and nervous, not really sure.  How do I stop this.  As well sometimes he can be aggressive to strangers (circling, barking, appears to go for ankles, but no biting yet)

Answer
You need to train the dog and the kids together:-)  Firstly, the children should not be permitted to play rough near the dog.  The reason is that dogs get very, very good at behavior they get to practice, and that isn't the behavior you've said you want your dog to do.  One strategy that I use, also, is to exercise the dog heavily before the kids interact with it.  These dogs are hard wired to want to stop motion, so this is normal herding displacement behavior.  But, you want to eliminate most of the triggers for it and then start training some incompatible behaviors that you can ask your dog to do instead of chasing and nipping.  Aussies are not always everyone's friend, and will naturally be reserved with strangers.  It's safest if the person comes in and sits down and then your dog gets to come and check the person out by sniffing (people should not reach for the dog, just let the dog sniff and go on about its biz).  Let every stranger who comes in pick up a dog biscuit at the door and drop it on the floor for your dog to pick up - you are creating a situation that tells the dog to regard strangers as cool.  Do lots of training!!! Take the dog to a good clicker class - Aussies are so good at it:-)  Then you will have some cues to use to get your dog to "leave it", "come", or "down" instead of chasing.