That's kind of a broad question. Are you referring to some pest in particular? Roaches, ants? In storage, campgrounds, or boon docking?
We carry diatomaceous earth to spread around the wheels, jacks, hose and power cord if we expect a bug problem. It's not poison, so it can be used inside and out. Must be reapplied after a rain.
We got the worst ant infestation we've ever had inside last summer, and it took weeks to finally eliminate them, several states away. Used the DE plus a few Terro baits.
When we get back home and expect to be in storage for awhile, we'll use a bug bomb, just in case. We usually don't see many dead bugs, but will keep doing that. Gotta be careful that doesn't get on anything that touches food.
Bad decisions make great stories!