I guess this is a human's response to animal food noises. I just remembered one night when I was about twelve being woken up by a regular clanking noise. We lived in the country on a dirt road and late night clanking wasn't normal. I looked out my window to the back steps and saw two cats sitting on the steps staring at two raccoons. The raccoons had come to eat the dry cat food we put out. A third cat, Ursa Minor, was bravely facing up to the raccoons and startling them by banging on her side of the tin dish so that it clanged on the concrete. Each time she did this the raccoons backed up a couple of steps. I watched until they disappeared into the trees and then I went back to bed and sleep.