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

https://marcosgnc317.clearhavendigest.com/posts/common-entry-points-rodents-use-to-get-under-san-diego-homes-3

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.