To be honest, did they smell like urine? They could be cooking their own meth and selling to support the new car and their habit. I would either call protective services and the drug task force in your area and drop a dime, you can be anonymouse or definately one or the other. It is damaging the kids emotionally growing up neglected, and possible abuse if they are cooking. The chemicals used to make a batch is unreal and what it does to the kids is amazing, just breathing it and getting it on their skin. I am sorry you have to deal with this, but foster care has got to be far better than where they are at if you cannot care for them. What about other family members, could they care for them for a bit?