Language Part 3
They make noise to claim space.
It can be very irritating. Since part of the space they are claiming seems to include me, and snippets of song and random comments and the periodic insistance that I stop what I'm doing and look at them even though what they've done is come into my office and sung, I dunno, part of the Green Acres theme song and then laugh because they think it's funny doesn't feel near as entertaining to me as it does to them. (That's a hypothetical, no one has ever actually come into my office and sang the theme song to Green Acres.)
But I think part of the point is that it is about them and not someone else.
It's communication at its most basic. 'I am in control of this space.' It's as fundamental as pheremones. One of the things that silentmeow's humming does, although I think unintentionally, is fill space.