I've had LEAFs for 6 years, and one nagging problem has been the incursion of rats into the hood area. They seem to love getting cozy (and pooping on) the electric engine surface at night, whether or not the car is being charged. Fortunately, they haven't done any damage to the car's wiring or tubings yet -- but it's been a struggle trying to keep them away.
I refuse to use poison, various applications of smelly liquids have not been a deterrent, and although I've managed to catch a few in rat snap-traps the critters have somehow learned to avoid the snacks I leave for their temptation. I've read about using mothballs and other strong-smelling substances to turn them away, but I really don't want those to smell up my car. The idea of battery-powered lights and noise generators (available via Amazon and elsewhere) seemed like a possible next step, but before going with those approaches, I decided to try something much simpler and it seems to be working, so I figured I'd share it here.
Specifically, as illustrated in the photos below, my LEAF has a nice protective cover that we keep on it most of the time -- and more so, now that our 2019 Bolt Premier has become our primary vehicle. As the photos show, the LEAF is parked in our driveway, facing the door into the house, which has a relatively dim LED light beside it that goes on/off automatically at sunset/sunrise. So what I do is keep the LEAF's hood propped up by an approximately 7-inch inverted unbreakable plastic container, underneath the dust cover. Then, each night I slip the car's dust-cover up to expose the opening in the front hood and allow fresh air, and enable light from the entry door's outdoor light to illuminate the under-hood area. And each morning I lower the dust-cover again to provide cover to the hood area. This way, there's no need to worry about batteries or whether under-the-hood electrical deterrents are functioning. Also, since the LEAF isn't driven on a daily basis, simply lowering the dust-cover during the day saves the need to unlock the LEAF and pop open the hood every evening at sunset.
Below are a set of photos showing my (hopefully) successful simple solution to warding off the rats. In order (top to bottom), they show: (1) rat droppings on engine, and (2) rat nesting evidence on battery -- prior to this experiment; (3) my LEAF covered up in the driveway; (4) view of the propped up hood, as configured for nighttime air & front-door light exposure; (5) view of the propped-up hood with the dust-cover lowered during daytime.
Below: evidence of rat droppings and nesting materials atop the LEAF's engine
Below: partially completed "rat's nest" atop the LEAF's 12VDC battery
Below: nice cover keeps LEAF clean
Below: "night mode" -- LEAF's hood area partially open and uncovered
Below: "day mode" -- LEAF's hood area partially open but covered
So far, this approach has been working perfectly, with zero evidence of rat incursion since it was initiated. Also, it doesn't require the use of battery-operated gizmos, smelly sprays, or dangerous poisons. In particular, in order to use the car, we simply remove the car's dust-cover, remove the inverted plastic container and snap the hood in its normal closed position, get in and drive off.
NOTE: I'll update this post in the (hopefully unlikely) event that my simple open-hood deterrent proves unreliable over a longer period of time. I've been a strong advocate of the K.I.S.S. principle, and this is a good example of its use