Well, I had a little issue with a rat or possibly giant mice. My new truck, which was sitting in the garage while I drove another car, became home to a rat or mouse family. I wouldn't have minded, except when I wanted to start driving my truck again, it was dead. DOA. Kaput. It got towed to the dealer who deemed it a catastrophic failure. Two days later, they announced that they found a mouse/rat nest in the engine, and the little bugger(s) had chewed 10 wires. I am all for live and let live, but I need a kind way to keep these guys out of the garage! Any ideas? I've heard that super-sonic sound device doesn't work and I am too soft hearted to kill them.
Peppermint oil .. soak a cotton ball or little paper towel square.
This. Refresh it every now and then. Also don't leave it to sit as a tempting home, make sure the area around the truck isn't inviting (no easily accessible food/bedding materials,) and it's gross, but if you have cats or access to cat litter, or know someone with pet rats even, sometimes used litter put around in little dishes can also help put up big 'go elsewhere' signs - I'd do that in the general garage area near the truck. (I mean, it doesn't have to be super-stinky because rodents have very good noses, but it's still used litter. I saved take out containers and used them so I could just throw them away as needed.)
Basically, you want to make it look as little like a hospitable rodent residence as possible - no all you can eat buffet, no Bed Bath and Beyond Superstore for mice, "NO VACANCY" signs implying something else already lives there, that sort of thing. I think the sonic thingies can help in making a place seem less hospitable, but if the area is otherwise super-tempting then they'll just ignore it.
It isn't perfect, because your place might still end up looking better than any other place nearby and then you'll have problems anyway, but without killing them that's about all you can do. (And honestly I think in some situations, trying to kill them is a losing proposition anyway - I mean, rodents are out there, it's just the way things are. If you get rid of one group of them, sooner or later another group is going to realize there's an area with no competition and move in again if it's still inviting, you know?)
I loved your story, Bluey! The garage is completely clean now, as of this morning. We found more "seed" stores, and another nest. Also found a baby bull snake! Since I live out in the middle of the desert, I'm used to all sorts of wildlife and was thrilled to see the widdle baby snake!