If you live where there are citrus trees, there will be rats. Phoenix, Glendale, Scottsdale, high income, low income matters not.
I was changing motor mounts on my wife's minivan last year and I noticed that the hood insulation looked a little ragged. I didn't give it much thought until I noticed the label from a radiator hose sticking out of an inner fender, and some burned-looking hair on the catalytic converter shroud and some sort of stain on the serpentine belt.
Wearing nitrile gloves, I started pulling gobs and gobs of the hood insulation out of the right fender, but no rat. My wife commented that the car had smelled like hamburgers cooking about a week earlier. She had checked under the hood and checked the fluids, but everything looked OK and the car ran fine. The smell went away after a while. It seems that the rat got flung toward the back after getting snagged in the serpentine belt and got cooked by the emission control device. The wiring was OK also.