This is a Re post to help OP with chipmunks and may help others with pests..
One idea (not mine) that I've tried with success (4 years running) is to start by:
1-Checking all entry points under my trailer IE: Gas lines, elec, waste pipes etc. 2-Purchace a roll of 1/8 inch mesh, Zinc coated (heavy duty) screen type material, (hardware store).
3-Cut with a tin snips into 2 inch by 12 inch strips (like a ribbon).
4-Find 1/2 inch self tapping screws also at the hardware store, and small flat washers. Now the easy part,
5-Start from front to back and look under you camper, look for the aforementioned lines, pipes, hoses etc..
6-Take the ribbon of mesh screen and wrap it around the line like you are wrapping a finger with a band-aid, leave part of the mesh against the floor and part against the line, wrap around until the mesh ribbon has gone around at least twice.
7-Now while holding pressure on the mesh against the floor with one hand, run a washer-ed screw through the mesh and into the camper sub floor, remember, to hold the mesh tight against the floor.
8-Continue wrapping all areas under the camper. The mesh screen is very form able to odd shapes and will hold tight, and it will remain rust free with its Zinc coating.
9- Purchase Ajax or Comet Powder Cleanser (with bleach)
and sprinkle around the tires, jack stands and tongue jack. Mice cannot stand the nose burn of bleach and will keep away from the smell of the bleach, and they will not get used to the smell. Mice travel with their nose and sense of smell and follow trails of (urine) left behind from the mice that broke the trail and entered your campers. A light sprinkle is all that's needed. Repeat applications as needed following rain events etc. It's cheap and goes a long way. It has multiple uses too, keeps the farm dog from re leaving himself on my camper tires, must burn his nose too.
10- Now set your traps inside and catch what (unwanted guests) mice that are remaining..
NOTE: No new mice will enter due to the wire mesh and due to the cleanser (with bleach) burning their noses.
Another trick for bugs, spiders,hornets, Yellow jackets, mud daubers etc. is to buy a dog flee collar, (the ones that look like jell), and cut each collar into 2 equal lengths. Place one length behind the fridge (outer) access panel, water heater outside access panel, furnace, etc.. Those creepy crawlers will not care to take residency anywhere near that smell and will keep those areas (bug) pest free for up to 3 months. hope this helps some of you with the mice and/or bug problems. My 2 cents........ RR.