Let me tell you about this! I too live in a rural area and park my Prius in the garage. I park next to where I store my wild bird seed in enclosed containers.
I began hearing a sound, like the crunching of leaves, every time I turned on my air. After awhile, I asked my husband to check out my air filter. We found pounds (yes, literally pounds) of bird seed stored in my air filter. Guess who? This burned out my fan that moves the air in the car. It had to be replaced at great cost due to the location of the fan. What a mess! Beware! Check the air filter frequently!