Mice in a crawl space may reveal themselves through scratching sounds at night, droppings, chewed openings

https://johnnymgsm588.image-perth.org/how-drafty-attics-drive-up-escondido-energy-bills-1

Mice in a crawl space may reveal themselves through scratching sounds at night, droppings, chewed openings, nesting material, or even unusual pet attention.