The reason cats shed so much is that they are trying to reach cat hair equilibrium. Cat hair equilibrium will occur when the surrounding space has the same density of cat hair as the place from which the cat hair emanates, namely, the cat. Under this theory, the cat will eventually stop shedding once we are so deep in fur that we are unable to breathe.
A corollary to this theory is that diffusion occurs faster when the gradient between the high density fur area and the low density fur area is larger. That is, the more you vacuum, the faster they shed.
Related: #2 claims this furminator reduces her cat by 10% upon use. It doesn’t seem to stop him shedding, but it does make him smaller! Perhaps there is a complex equation about changing surface-to-volume ratio. One time (on a previous cat) I decided that I would keep brushing until he either quit shedding, or was naked. After an hour neither had occurred, and I gave up.
Do you all have any corroborating or denying evidence? Alternate theories? Stories of ginormous cat-hair tumbleweeds?
Grumpy Rumblings (of the formerly untenured) 
June 29, 2011 at 5:23 am
I got my cousin the furminator. She has 4 cats. Neither of us realized it was essentially a big cat shaving device, but it is effective. I hate when I go over someone’s cat house and get fur in my mouth. It doesn’t usually happen in single cat households but I know several people with 3+ cat homes.
I could never do it. I would go insane. Trying to remove cat hair is like some kind of chinese water torture. It never stops. Unfortunately, due to my allergies, that just means that I have to limit my time in those people’s homes and/or make dates in neutral kitty free zones like a coffee shop or my house.
June 29, 2011 at 1:16 pm
Sad to be allergic. The furminator does help, but it doesn’t stop the production of new hair! Now we know why cats sleep so much: their whole metabolism is focused on producing more fur…
June 29, 2011 at 6:53 am
I consulted my cats about this situation, and they just laughed and wanted me to tell you, “Silly humans, you think we cats obey the laws of the universe?”
June 29, 2011 at 1:17 pm
Fair enough.
June 29, 2011 at 8:11 am
All that hair shedding is really for the benefit of the birds. When birds build nests, they like to line them with soft things like hair from mammals. So the cat shedding is creating conditions that benefit birds, which of course are a cat’s favorite thing to watch/catch/torture/eat. Good theory, right?
June 29, 2011 at 8:24 am
if only they would limit their shedding to outside! I suppose though, they try to… If only the servants would keep the doors open.
June 29, 2011 at 8:24 am
[…] of pets, Nicole & Maggie have a hilarious general theory of cat hair over at Grumpy Rumblings of the […]
June 29, 2011 at 9:13 am
My dogs resemble this post!
I’ve had very good luck with the furminator for dogs, too, but only in a relative sense. The amount of fur my dogs can generate is truly remarkable. I’d claim I’m only doing it for the child, but per the latest science reported via the Times’ Well blog (and that’s where science is reported, right?) as long as he was exposed during his first year (and he was, he was), we’re good. So I guess I could parcel the dogs off now, but we’re fond of them.
June 29, 2011 at 1:19 pm
I’m sorry I am still stuck on the fact that your cats let you brush them?!?!?
June 29, 2011 at 1:24 pm
#2’s cat.
June 29, 2011 at 3:33 pm
My cats like to be brushed also, but I started brushing them when they were kittens.
June 29, 2011 at 5:35 pm
Yes, my cat lets me brush him. I credit the people at the humane society who started brushing him when he was a wee kitten. I have brushed him ever since. I do it when he’s eating, because otherwise he wants to play with the brush. However, it is always a struggle to trim his nails! He hates that.
June 30, 2011 at 4:00 pm
Cats in the northern hemishpere are shedding a lot now because it’s getting hot outside.
July 3, 2011 at 11:45 am
Well yes. But does it have to be *projectile* shedding?
June 30, 2011 at 4:29 pm
I assume the fur-making abilities of a cat are equally proportionate to the time it thinks you should pet it (see The Oatmeal’s the correct way to pet a cat). Also this story in Wired seems pretty timely for this post: http://www.wired.com/underwire/2011/06/cat-fur-jewelry/
June 30, 2011 at 4:46 pm
uck
June 30, 2011 at 7:46 pm
I’ve heard of people vacuuming cats, though I’ve never met a cat that didn’t think the vacuum cleaner wasn’t its mortal enemy. Meanwhile, of course, the vacuum cleaner is like “what, you’re not my arch nemesis, I’ve got bigger fish to fry.” Anyway, space suits…with tails. Or maybe a giant hamster ball, put a couple ounces of catnip in there and maybe they’ll exercise off all their fur.
July 10, 2011 at 7:52 pm
My sweetie is a vet and informed me (when I was laughing and reading him this post) that cats don’t shed because of the temperature. They shed more when there is more sunlight. So for those of us who live in the Northern hemisphere, our cats are shedding more now. As the days get shorter, the shedding will slow as they hold on to it for the winter. Amazing the trivia that I manage to learn! :)
All of that to say .. my cats are driving me freakin’ insane with the shedding. I actually used the lint roller on one of them the other day while I was rolling the sofa. It didn’t make a dent. If I were to gather up all the fur floating around the house right now, a day later, I could probably make another cat.
July 10, 2011 at 7:54 pm
One of our cats makes new cat sized furballs every two days! We *thought* she was a short-hair when we got her…
So the mechanism by which vacuuming causes more shedding is that more sunlight is able to reach the cats (since the ambient fur/air density is lower)… interesting….