>>Often when I go camping I have problems with mice getting into my
Westfalia.

I had the same problem until I did two things:

1) Close off the holes in the main battery compartment with wire mesh.
These are pretty big holes that a rat could get through.

2) Mice like food. Keep all your yummy smelly stuff if sealed Tupperware
type containers.

If you do get any, a trap with peanut butter works nicely. WARNING: hold
no quarter with these varmints. They can quickly destroy a van's wiring,
pee everywhere, reproduce at an amazing rate (litters of 10 are
average), AND they are known to carry nasty diseases. Do not ever vacuum
up mouse droppings as they could be carrying the before mentioned
diseases and you don't want to inhale any of it. Clean it with a bleach
solution.

As to the ultra sonic devices, all the sources I have read say these
things are a waste of money. Keep the food closed up and the van clean
and you will be fine.

Scott
85 Westie
Seattle