where on god's green earth were the parents

These kids looked all of 15 years old, and I never saw a parent, nor any indication that a parent cared where their child was, or if the child ever came home at night.
Great movie, but I thought that was kind of weird. I also thought the car destroying scene was strange. Made me think these kids might be pseudo-socio or psychopaths themselves, there didn't seem to be a shortage of those in this film.