We have a problem with rats here in So. Cal. So many cars are being towed to repair shops with their wiring harnesses chewed up (my wife's car was one of them). We tried rodent spray (made of a mix if peppermint oil, hot pepper extract, and a bunch of foul smelling stuff), we have lights on around the house, we added little electronic gadgets that emit sounds and are flashing in our car's engine bays, moth balls, peppermint oil soaked cotton balls, etc. - they all work. - For a short wile. After that the critters get used to them, and make themselves right at home again in the supposedly hostile, stinky and noisy environments (to them). They are the most persistent animals imaginable. Our neighbors have gardens and fruit trees, so there is plenty of food to eat for them all year around besides wiring harnesses. And of course, little motivation for them to look other places to stay when everything is provided for them in the neighborhood.