A dirty crawl space should not be ignored, since rodent droppings, urine

https://telegra.ph/How-Drafty-Attics-Drive-Up-Escondido-Energy-Bills-How-Drafty-Attics-Drive-Up-Escondido-Energy-Bills-09-02-3

A dirty crawl space should not be ignored, since rodent droppings, urine, and nesting debris are biological contaminants that can affect the air inside your home.