Mice and chipmunks can do incredible damage in a short period of time to a car engine compartment, and snowmobile, boat or ATV. THIS is the time of year they are looking for a place to spend the winter. They bring nuts, and leaves and anything else right with them...and of course once they find a nice warm dry place, they invite all their cousins along too.
A good cat is well worth some food every so often for sure, but in the absence of that, I have found the decon spread around the outside of the buildings is far better than spreading it around inside the building. Get them to eat it before they find a way in...cause once they are in, they will pack the poison food away right in what you want them to stay out of...sort of the opposite of what you are trying to do....but they do what comes naturally and they store for the long winter.
Inside the garage, I put traps around and bait it with peanut butter or bacon...so if any do get past the poison barrier, then they will likely get into the traps.
Don't use poison with cats tho, or you will probably kill the cat right along with the mice.
The best defense is an offense....unless you are the Detroit lions, then you just sort of lay down and play dead....cause you don't get hurt them....