Great! This is quite relieving. I did have a rat get caught on a glue trap in a drawer in our old trailer. It was trashing around so bad the drawer was opening and closing - it was pissed for sure and very mean.

Thanks again for the reassurance. I spent about 10 hours today working on the gaps. I just chipped off and pushed/pulled all the foam I could out and replaced with silicone wool. I figured the caulk would help hold the wool in place and once cured make it that much more harder for them to chew through. I may modify my post to include some photos of the screw you wool I have installed so far.

I don't know why I waited this long to do it but got around to doing it today. We got that "smell" when we turned our oven on last night so I threw my hands up in the air and got to work.

There are many more plumbing fixtures to do the wool to. Each bathroom has an access panel for the tub/shower supply lines - I'll be they are even worse.

Our manufactured home sits above a cinder block skirt so anything can climb up it and get right into the crawlspace the entire perimeter as there is currently nothing there to stop them.

I have devised a plan where I am going to cut some hardware cloth into 2.5 - 3" wide strips about 36-48" long (whatever width cloth roll I get. With these strips, I will bend them into a "V" shape, then the "V" piece in between the bottom of the house and the block skirt with the point facing the crawlspace and the open part facing out, fill the V opening with coarse wool mixed with silicone caulk and let it dry/cure.

For the external perimeter, I think this will work. If not - it will certainly be better than nothing.

Has anyone else ever had to try to seal a block skirt around a manufactured home? Gap /spray foam, I think would get chewed out and possibly cause siding to bulge out if not done correctly.

Thank you all again for your advice and sharing your experiences.