I have a cat who must have some Siamese in him. He screeches like a lost soul, wails like an abandoned baby, howls like a banshee; and all pretty much because he can. He does it to let us know it's time to wake up; he does it to let us know his food bowl is empty; he does it to tell us we're in the wrong room, and he wants us in another room, or he won't stop howling. Sometimes he does it, in Wallace Steven's felicitous phrase, just to test the reality of the rooms he lives in.
Seems true for that portion of the population that manages to get itself in the news, too.