As was posted, a rodent infestation means...work. Whether the OP takes it on or hires it out, it is the same. Sure, a single mouse, only nesting once, and having a single litter, then all mice eliminated, may mean less intensive cleanup measures. My experience is that once they move in over the Winter, there is just non-stop procreation and population increase.
A side-benefit from removing the belly covers is that a user can better position ductwork, arrange for better insulation, and the most important, understand what is installed in those spaces. Most guys that get into those locations discover pinched ducts, poor wiring techniques, and insulation that is haphazardly positioned. Member LarryJM did a rearrangement of his under-belly area and has posted pictures and details of his work.
BTW, they don't make enough dryer sheets to eliminate the smell of a full-on infestation.
