Via the air intake.  A mouse only needs 1/4" opening.

I have had mice nest in my camper, two places.  1) air filter housing, 2)
under the refrigerator.  Both were deer mice, and brought in their own
nesting material, in the form of dried grasses.  Also brought in some
sunflower seeds, probably from my bird feeders.

So, I have put Irish Spring bath soap in a few places around the van.  I've
seen no evidence of mice since.  Could be coincidence, of course.

But what brought my friend's Eurovan down was a wood rat, and the nest was
made of sticks.

mcneely

On Tue, Sep 5, 2017 at 6:48 PM, Dan N <dn92610@gmail.com> wrote:

> I serviced my daughter's vanagon recently and found a mouse nest in the air
> filter box... the air filter all chewed-up .. no clue how the mouse get in
> there...
>