Could someone please point me to where could I find more information about 'drive'? Any books or websites anyone could kindly recommend? I don't hear about it much in person (I don't have friends or colleagues who are in this kind of area) but have seen it mentioned on the internet. My dog is dog aggressive, trainer said it's because she wasn't socialised before we got her as an adult, and on walks she expresses the body language dee lee mentioned - freezing, ears pricked. I am not sure if what she's doing is drive, I'm quite confused about it, but I would like to read more so I can understand her better.