Many times the mouse poison causes the mice to be thirsty, and they leave the area (or camper) to find water and hopefully die out there somewhere. So if you don't have dead mouse smell in your camper than that is what happened. Dcon and Tomcat poison pellets are very weak and sometimes don't work. Try Ramik (green packaging), and especially One Bite (yellow packaging) works well for me.
Avoid putting the bait in the camper - it will draw the rodents into the camper to get the bait. Use the outdoor bait containers (designed to prevent other animals from eating the bait). I put those next to the jack and wheels, where rodents can crawl up into the camper.
Rodent control is hard, and never ending. Try variations of all the advice you read about here. Eventually you find some combination that will work for you.