On Thursday, I woke up early and took out the trash, leaving the garage door open. Two hours later, carpet cleaners arrived. One of them located me as I worked behind the house. He said there was a big dead rat in my garage. Sure enough, it was the same one I'd killed the day before. Perplexed, I deducted the following:
1. A large bird or animal seized the carcass, but for some reason dropped it by chance in my garage.
2. A human being(s) walked onto my property, into the drainage ditch, picked up a big dead rat, and placed it inside my garage.
3. Using cosmic rays, aliens reanimated the rodent. Seeking revenge, it attacked but expired once more before reaching me.
4. A human being(s) walked onto my property, into the drainage ditch, picked up a big dead rat, and accidentally dropped it inside my garage enroute to taxidermy class.

Then there's this possibility.
I invite theories.