Thanks so much for getting back to us. In answer to your questions: 1) The pup was 12 weeks when we got her. 2) No, I walk her every morning along the roads near where we both live and she has never behaved this way. It is only ever when we take her for an evening walk in the fields or the woods. She could be on her lead or off, and it still happens. 3) By working variety I mean old type i.e. not heavily wrinkled, show variety, but more lean and athletic with more stamina. Both parents were temperament tested with trained agitators and are working type Neo's also. 4) Yes, in the home she is well behaved, obviously craves attention like a typical puppy, but pretty good at basic obedience. She will sit and lay down on command, will wait if we need her to and is generally friendly. She does have a tendency to "nip" when we prevent her from climbing on the sofa or something like that, but we always make an "aargh" sound and put her in her bed if she does this. She does have an annoying habit of getting quite hyperactive until she has been well exercised. She will charge into the living room and side swipe into the sofa, sometimes growling whilst she does it, but we just put this down to boredom and wanting to be taken out. She is generally a very highly strung animal and will whine a lot until she has been walked, but once she has been for a run, acts like a totally different dog around the house and you don't hear a peep from her. 5) She ONLY ever does this in the woods/fields, more so when she is off the lead as she starts running round in huge circles. We don't think this could be fear based as there is nothing around her at that time that she is frightened of. She is nervous of large vehicles such as lorries, and will pull round a corner on her morning walk to get away from them. She can also be nervous of loud noises, for example if my fiancee accidentally drops something in the kitchen. But obviously none of these factors come into it. She is not remotely nervous of people, in fact quite the opposite. She is extremely friendly when she sees anybody and only ever guards on the property. We have tried really hard to pinpoint what could trigger this behaviour, however it literally could be any time of day/night, on lead or off (but mainly off), any wood/field. The only thing that seems to be constant is that it is only myself and my fiancee around when she does it, as if there are other dogs/people about, she is more interested in them. We have gone back to the breeder and asked them about this behaviour. he seems to believe that this is common in the dogs he breeds and puts it down to playfullness and the breed being particularly boisterous and dominant. He also said that she will grow out of it. We really hope this is true, as it is ruining a big part of owning the dog and is putting my fiancee off!! But as yet, we have seen no signs of this stopping any time soon.