We've had squirrels and rats in our loft. Squirrels might sound cute but they're noisy and destructive bastards that keep ripping the side of my roofing off to get back in.
We tried the flashing lights which are supposed to deter them, together with a sonar noise thingy. We even put a radio up there as we read somewhere that they don't like environments that are noisy.
With the lights and the music, I think the squirrels thought we'd laid on a disco for them! They didn't give a shit.
We periodically had rats too. We live in a town but it's in the south west and there's countryside very close by.
I get it OP, it is upsetting to know there are rodents in your home. It feels dirty and embarrassing but honestly it's so much more common than you think, and you haven't done anything wrong.
One thing I'd also suggest is to make sure your garden isn't rat-friendly. So no food out for the birds, make sure you're not leaving any dog food etc around. If you can, make it an open space - rats prefer to sneak around under cover.
On the plus side, rats are infinitely easier to get rid of than squirrels (or at least they were for us). We tried all the non-lethal methods of dissuading them such as citrus and mint smells. Made no difference. We resorted to rat poison. The smell of death or illness is supposed to deter other rodents so that might help too.
Solidarity OP.