What they hear is senseless noise. It's like us trying to discern emotion in the hum of a hair dryer or the chortle of an engine as it fails to turn over. That's the drawback but also the glory of creatures that were never domesticated. Nothing feels better than being singled out by something that at best should fear you and at worst would like to eat you. I think of the people I've known over the years who've found a baby raccoon or possum and brought it home to raise it. When young, the animals were sweet. Then one day they became moody and violent,