I agree with Rock on the genetics thing. We've never had a "kicker" dog until we got this little min pin. It's not a problem at home because we do have desert landscaping with pea gravel instead of grass in front, and brick patio all over the backyard. At the park, this girl kicks dirt up with all the vigor of a ticked off bull. Also, she has really hard, solid nails, which are even more effective. We pull her off, if it is lawn, but let her do her thing if she's pottied on mulch. To try to break her of the habit would no doubt make us all neurotic. I don't know if it's a min pin thing, but it's definitely a Darcy thing. We have learned not to stand behind her and not to let our other dog stand behind her, either. :R