It is a tribal dance, by our indigenous people here in NZ, the Maoris, used as a greeting or challenge, our famous rugby all black team perform one before they play, although it has caused some controversy to say the least, i really cannot understand why?

So the girls went to classes to learn and do it for you as a greeting of course.
If you go to www.youtube.com you can see one performed.,type in Maori Haka and then you will see the link and you can see it.