The usual answer, of course, is: To clean themselves. There are other answers:
Some people think it is used as a way to control their temperature – it keeps their fur smooth, which in the winter traps heat. In the summer, it spreads saliva on the fur and cools them down and can also loosen fur so that they shed more easily. Others think it is a natural way of reducing parasites like fleas or ticks.
Perhaps cats lick themselves to ingest more foreign bacteria and dirt, which they need to be healthy. Test of this proposal: Feed a cat more fermented food, it should lick itself less. (Just as I became less of a foodie when I ate more fermented food.)
Then why do they lick their kittens? In my experience the best determiner of how much grooming a cat does is how nervous it is.
Yeah, no. I love you, man, but you are wrong here. As Nathan says, cats will clean more when stressed, but really, it primarily is to clean their fur. Ever see a cat who cleans too little? Matted fur central. It’s not pretty,
There’s got to be a “why do dogs lick themselves” joke in there somewhere…
From the inimitable Dr. Boli (a humor blog): “A cat’s fur contains all the nutrients the cat needs to survive, which is why cats spend so much time licking themselves.” https://drboli.wordpress.com/2007/06/29/from-dr-bolis-encyclopedia-of-misinformation-2/
I have read that animals produce vitamin D in their fur and ingest it through licking. Human vitamin D lingers on skin and is slowly absorbed, but I always assume that’s what my pets are after when they lick me. Can’t remember the source, sorry.
Hey, that reminds me of a joke! Two drunks are walking down an alley and see a dog licking its private parts. One of them says “Boy, I wish I could do that.”
The other one says, “Maybe you should try petting him first.”
I always thought the reason pets lick people is to absorb the salt and minerals that linger on skin due to perspiration.
I had also read the thing about Vit D and cats; however, I’m skeptical as my own cat tends to lick himself the same if not more when he’s allowed to go outside.
I think the grooming function of cats is probably more akin to general cleanliness — insuring that not too much bacteria/bugs/dirt gets lodged in their fur, which could cause infection. This might be somewhat akin to why you need to wash your sheets — there’s a balance here.
Cats also have raspy, comb-like tongues, which I think has been argued is because they evolved to be able to lick marrow out of bones, but perhaps its also to manage the fur.
Anyway, I feed my cat fermented foods regularly and my cat food also has probiotics in it IIRC. I also regularly give my cat yogurt or kefir. However, my cat is neurotic as hell about licking himself. He licks his fur right off in some areas and I’ve been trying to self-experiment my way into figuring out what the problem is. Most recently, I’ve taken him off crappy cat food and put him on a no-grains, high protein based food and that *may* be causing an improvement — have to wait a couple more weeks to see if his fur really is coming in across his whole body (it definitely is in certain areas, but too soon to tell if its a complete cure).
You can hypothesize about many explanations but as others have said self-dosing with vitamin D is almost certainly the main reason. I had this exact same discussion with a colleague a few years ago (I’m an ethologist), a few studies had been done and he was contemplating seeking funding to investigate further. I’m in the UK where UVB is absent for the winter months and much depleted in the autumn/fall and spring. Here there is a noticeable shift in behaviour from summer to winter; in general cats are fairly laid back during the summer, sleeping lots and not getting upto much; during the winter they sleep less, become more agitated and hunt much more. If you exclude the late spring high when there are lots of fledgling birds and young mammals around which present easy prey for cats there is a distinct increase in prey brought home by domestic cats during the winter months compared to the low of the late-summer/autumn. Looking at the remains of these prey items and usually what is eaten is the head and ‘guts’ (the liver probably being the desired morsel) — the main concentration of vit. D is found in these parts. Looking at my cats’ behaviour and there are some distinct types of grooming. It is the ritualised, almost neurotic, licking of paw, rubbing ear & temple, licking paw again … that I suspect is the main ‘vitamin D dosing’ type of grooming. Of course vitamin D is produced throughout the cats fur but this specific type of grooming is much more noticeable/frequent during the winter months with my cats and I take this to indicate that they are getting/are deficient in D3. Unfortunately I don’t think the study ever went ahead (bigger and better things came along), it was hoped/thought that by getting cat food manufacturers to supplement foods with D3 that it would reduce the impact cats have on the native fauna.
@justin — you may like to try supplementing your cats food with D3 or even rubbing some D3 oil on your cats ears/temples. It would be interesting to see if this results in noticeable behavioural changes.
Since cats don’t synthesize Vitamin D (run a search on NLM Gateway if you need the research), so that’s not why they lick their fur. If they groom more in winter, maybe they’re just fidgety.
WOW! I never realized there were so many diverse opinions on a subject as simple as this. It’s simple…. Most home in America don’t have kitty showers built in.
I read somewhere that cats groom constantly in order to minimize their own odor so that it won’t give them away to the prey when they do their solitary hunting. Dogs (wolves, really), unlike cats, evolved to hunt in packs, and use their natural scent to keep track of where other pack members are, so that function overrides / makes unnecessary minimizing their own scent (pack hunting techniques mean it doesn’t matter if the prey smells the hunters once the hunt is on).
Just another hypothesis, I guess.