Basement drop ceiling: insulation and mice

Hello,

I’ve been having an issue with rodents in my drop ceiling. This has created a musty smell which I’ve mitigated by a) catching them (which I think I’ve finished), b) pulling out a portion of the insulation and replacing drop ceiling tiles and c) air fresheners.

It’s about ~600 sq foot space that I think at this point I need to replace all the tiles and insulation while trying to solve the entry point issue. This will be a messy job given just how much chewed up insulation, poop and nuts I’ve encountered already. Obviously I don’t want to replace everything without solving them coming in so I recognize that’s my main objective. Having said that I had been quoted for tile replacement alone at $7900 or $13 a square foot and the company isn’t even sure they remove insulation as they don’t typically insulate ceilings just the walls (person was a rep not a crew person for the company so I think I’m getting the high end of quotes)

This brings me to my other question, do I even need to re-insulate the space? I see a lot about people just insulating the rim joists in which case can I avoid the fiberglass insulation all together? Is there anything superior and even rodent resistant? I see spray and foam board as an option. It’s a tight space from the ceiling grid to the rim joist so I worry just how well of a job I can do by myself on this. Even the tile and insulation replacement has proven to be a heavy lift on my own in the small area I’ve done so far. Hopefully someone has experienced this before and can provide some sage advice. Thank you!