I use "Boric Acid". Put it in a coffee can, install the plastic top, then punch holes in it so it can act like a shaker. Sprinkle the Boric Acid around the tires, Jack legs, Sewer Drain Hose, Electric power cable, and anything else which they might use to crawl up into your rig. I find this to be the most effective means of manage these small pests! Good luck!