Yeah, that's reeally nasty. And yes, I am blogging about barf. There are some things we really shouldn't want to know about. But the question has been asked, and I must answer. Blech.
"Where do they come from? Where do cats store all that hair and why?"
They come from kitties who very conscientiously groom themselves. They keep themselves so clean and fluffy and nice that unfortunately they have gross consequences for this cleanliness.
The fur stays in a pile in their tummies until it just gets too big and then, "HACK, HACK" out it comes. Lovely. Just lovely. Right on my white carpet. Or my comforter. Or the middle of the hall so I step on it in the morning. Why thank you, kitty. That was so kind.
All I know is that I very fortunately got out of the "hairball-cleaning-up duty" and I am oh so thankful for that. I'll trade almost any job for that one. That and the litter box. Ugh.