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

https://augusttlpy976.moderncairn.com/posts/why-you-should-never-vacuum-rodent-droppings-in-your-attic

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.