This one is my fault.
I know I live in a hay field and park the car on the edge of it, over the wee bit of gravel. I also know that it is winter and that the mice, and they are legion, are running out of food.
I also know that I eat in the car and that that is a bad idea. The idea was to keep the mice out of the house. So not eating in the shed-home because that would draw mice, you see. And also, it would make everything in the wee space stink of whatever I just cooked. So a bit of soup and boiled eggs (which does make it stink of boiled eggs) now and then, boiled water for tea and coffee. That's about it for cooking in there this winter with a couple of exceptions (which is how I really learned that if you fry sausage in there, your clothes smell of sausage...all your clothes...and the walls).
Anyway, I haven't actually seen the mouse/mice in the car. But I've seen there work. By work, I mean poop. And a chewed finger of a glove.
So, I warned them and then put out some poison. Turns out De-Con isn't what it used to be. It's little bricks now, not the blue pellets. And it's missing the ingredient that stayed in the dead mouse bodies and poisoned whatever ate them, and whatever ate that, etc. So, the mice/mouse started munching on that. A lot. Either I had a lot of constipated mice (there weren't that many poops), OR I had one giant mouse with a high tolerance for whatever the lesser poison is in that little brick.
It ate for days. And days.
I was going to be gone for a bit and parked on pavement at the airport (stupidly I forgot the overall plan and parked near the shrubbery at the edge of the parking lot, but whatever, fewer mice than at home). I put out all the little bricks, 3 or 4 of them. And left it for 2 weeks.
I have seen no further mouse signs but I'm keeping an eye out and being very vigilant about keeping all car food in a sealed container. It will still attract them, but they won't be eating it. I hope.
Yes, not having food in the car would be even smarter, but also super inconvenient.
The car was in for oil this week and I asked if they saw any mouse signs in the engine...NO! Yeay. I don't know if I should put poison under the hood or if it is also a bait and every mouse would take a bite of wiring as it made its way to the poison-bate.