Will it hurt anything in my car to allow a mouse to build her nest on my battery?

Dear Car Talk

Dear Car Talk | Sep 01, 1997

Dear Tom and Ray:

I'm having a bit of trouble with my '89 Toyota pickup. It has 220,000
miles, and the driveline makes strange noises, the radiator leaks, and
it needs new shocks.
But that's not what I'm writing about. My biggest potential problem is
mice. When I looked under the hood to check out the radiator, I noticed
that something -- presumably a mouse -- was building a nest on top of my
battery. The little creature had taken pieces of cedar bark and had
built a nice, soft nest between the positive and negative terminals. I
brushed away the nest one day, and when I looked the next day, it had
been rebuilt. Will it hurt anything if I let the mouse have her little
nest under my hood? Or should I work harder at discouraging her? -- Jim

RAY: She's not hurting anything right now, Jim. And while the nest is
unlikely to drain the battery by creating a conductive path between the
terminals, there are a couple of other things to watch for.

TOM: One is an upwardly mobile move to the air cleaner housing. A lot of
mice gravitate to the air cleaner housing because they like the
material, and it's warm, dry and safe in there. It's seen as a step up
in the world of mouse housing.

RAY: To prevent that, I'd buy a small piece of hardware cloth (thick,
quarter inch wire screen), and cover the opening of the air intake. And
before you cover it up, I'd check to make sure she hasn't already set up
a weekend residence in there.

TOM: The other thing to watch for is chewed wires. Some mice like to
chew wires, and that can be disastrous for your truck. So if you notice
any signs of chewed wires, you probably want to call the DES -- the
D-Con Eviction Service.

RAY: But if she's not chewing your wires, and your air intake is covered
up, there's no reason you two can co-exist happily in that Toyota for
ever after. And who knows, maybe she'll start to feel protective of your
Toyota and growl ferociously at anybody who tries to hot-wire it.

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