Hello. With regard to pests in the camper, if they are the type that have an exoskeleton (spiders, cockroaches, etc.) a non-toxic solution diatomaceous earth. Some time it is mixed with bentonite clay. Get food grade.
DE feels kinda like talcum powder. It is mildly abrasive to skin; but, not unpleasantly so. However, to an exoskeleton, it is jagged and sharp. When the critter moves across it, the exoskeleton is pierced and they dry out. One can use it to kill some intestinal parasites I’m told. I met a man of 90 who looked 70 and said he mixed it in water and drank it everyday.
My first experience with DE came when I was dog-sitting. The 15 yr old dog liked to lay in the back yard in the sun. My first day on the job I noticed some big red ants digging a tunnel from her postage stamp sized yard back to their nest. The little hippie had a compost pile, the ants had discovered a food source and decided to take over. I called the moderately militant little vegan woman and informed her of the problem.
She said “Put some DE on 'em.” I replied, “But these are Big Red Ants!” “Put the DE on them!” she replied. I figured I’d do that for the two weeks and then let her deal with them from there.
I went outside, put a spoonful of DE on them and watched as the kept on digging.
The next day, I was surprised to see that they’d moved the location of their tunnel so I put another spoonful on them.
The third day they moved the tunnel spot twice in response to my DE application. At that point, I sprinkled some all around the yard and around the compost pile.
After 10 days the collective intelligence of the ants decided it wasn’t worth the effort and they left her back yard alone, never to be seen again. To me, that was the amazing part.
I’ve used lots of times since then. The stuff does work against exoskeletons!
Rain will wash it away. The critters don’t die right away. Some bugs are tougher than others. Harlequin bugs are especially tough. I’ve seen them survive for a coupla days in my food patch with DE on them.
It will also work to discourage ants if it is applied on the perimeter of an area to be protected. Put it in cabinets, wherever you want IF you want a non-toxic answer to bugs.
It is mild enough to human skin that I applied it where the sun don’t shine AFTER a visiting dog left me with a flea infestation. Even tho experts say fleas don’t try to live on human hosts, if a human is all that is available, they will take up residence.
Bug bombs work also; but, some folks don’t like the toxic nature. DE really works!