When I first started boondocking in the US southwest desert regions, I would sometimes see other campers with their vehicle hood left open. I didn’t pay much attention to it figuring they were using the truck or motorhome battery for camping.
It wasn’t until I first visited Organ Pipe Cactus National Monument that I learned about the Pack Rat (aka Wood Rat) and how much damage they can cause. They emerge from their burrows at night to forage, looking for food and nesting materials.

Unfortunately, they sometimes will crawl up into the engine compartment and chew on things like insulation and wiring. On a modern truck or motorhome, this can quickly cause thousands in damage and may render it inoperable.
By leaving the hood open enough moon and starlight comes inside to help keep the Pack Rats at bay. So, if you come across a place where campers have their vehicle hoods up and have night lighting set up around the RV take heed.
LED rope lights and lanterns are also often used deterrents. Here is an article I found with Pack Rat information plus some helpful tips and tricks.
Pack Rat Tip Video
See Related Post – Tips to Keep Pesky Mice Out of Your RV