Keeping mice out of boats, camps, etc is a pain. I have tried mothballs, peppermint oil and dryer sheets to no avail.
I keep my boat in a heavy duty Shelter Logic garage during the winter. I keep all of the compartments open, mice like dark enclosed areas. Since I live in an area that gets low temps and lots of snow, mice look for places to get into in the Fall before Winter sets in. I also keep an Adirondack Mouse Trap in the boat garage. It's a bucket with a dowel through drilled holes near the top of the bucket and a peanut can. Spread peanut butter around the peanut can. Take a 1"x1" stick with a nail through the end and prop it on the edge of the bucket near the end of the dowel. Also put anti-freeze in the bucket. The mouse walks up the stick, eats peanut butter, cans rolls and the mouse falls in the ant-freeze and drowns cuz it can't get out.
:lol: I posted a link of something similar to what I use.
At my camp, I keep an Adirondack Mouse Trap inside, but have not had a mouse get into the interior. They have been in between the main ceiling and the suspended ceiling. I have a few mouse traps above some ceiling tiles along with a box that they can enter, but not leave. This is kind of a pain. My new approach at camp is to kill them before they enter. I have a bunch of mouse bait stations around the perimeter. Each one has a 1oz Tomcat mouse killer block. They enter, eat some bait and disappear. I've been monitoring each one and noticed that they are not been eaten away as much. Good sign that they are dwindling and the rest will have to find somewhere else to live. In case you haven't noticed, I hate mice in my stuff!! Link to mouse bait stations below. Tractor Supply sells the bait by the bucket.
http://www.doyourownpestcontrol.com/protectajr_rtularge.JPG
http://www.tractorbynet.com/forums/...293d1266715312-inexpensive-mouse-trap-mt2.jpg