Crawl space rodents can affect the air inside your home because contaminated droppings, urine

https://chancenllf843.keystonescope.com/posts/why-escondido-homeowners-are-investing-in-attic-rodent-proofing

Crawl space rodents can affect the air inside your home because contaminated droppings, urine, and nesting materials may create particles people can breathe if the area is disturbed.