What Constitutes Are Safe And Sanitary Housing?

We (my children and I) live in a rental mobile home. I would like to know what should be covered under safe and sanitary housing. Let me describe our living situation. The trailer is infested with roaches, has holes in walls and floors, mold under kitchen sink, places where you can see the ground at wall/floor seams. There is insulation hanging down underneath the trailer, and holes in the duct work underneat that allows all kinds of animals to enter (like snakes, cats, mice, rats). We have brought these problems to the landlord. Nothing's happened. Live in Mississippi.