Here in NW Montana - we are plagued by Pack Rats - miserable , stinkin , pissin things !!
We trap em , fight em , shoot em - wage war on them all the time .
One thing that does seem to help ......is to leave the hood open , or just up halfway .
Seems to help . I'm in the logging business and we always are on the lookout for the little bastards . I hate em .
This little trick does help tho ...... Good Luck