heres some places where rodents can get into vanagons.  please feel  free
to add your ideas and then save this list!

-battery box vent hole (usually missing hose)
-front fresh air vent intakes behind grille
-westy flue vent inlet on drivers side
-rear hatch drain holes at bottom-
-vent holes in A and B pillars
- front shock access holes under the front seats (if the rubber plug is
missing)
-dogleg step pads (if the pad is not properly fixed down)
-missing seals around the a/c freon lines coming into the van at the left
rear
-missing seal around rear heater hoses or ECU harness under rear  seat
-missing seals around stering column base
-missing seals around front heater core hoses
-missing seals around rear a/c evap drain hoses into D pillars

feel free to add to this list...