Having a Baby vs. Having a Cat: A Response to The Oatmeal

The Oatmeal, a popular webcomic, recently published Having a Baby vs. Having a Cat. This is my response:

Ironically, the main reason I don’t have a dog or cat is that I don’t like cleaning up poop.


Cats: Incomplete Domesticates

It’s hard being a cat person in a dog-person world. 70% of Americans describe themselves as “dog people,” versus only 20% who claim to be “cat people.” Even among people who only own cats, a full 26% of them are “dog people.” (By contrast, only 3% of people who only have pet dogs are “cat people.”) [source]

The dog gets to be man’s best friend, while the poor beleaguered cat is associated with crazy cat ladies.


(I decided to give you a picture of cats instead of cat ladies.)

Dogs were the first domesticated animals, accompanying hunter gatherers on their exploits some 40,000 years ago. We’re not sure exactly how the first dogs began, but pretty soon people began actively selecting for certain traits in their dogs to make them more useful to humans.

Cats appeared much later–less than 10,000 years ago–and appear to have become tame via a very different route.

There is a special class of animals that have become semi-domesticated without humans actually wanting them, which includes mice, rats, and pigeons. These are not tame animals, but neither do they live in the wild , having become adapted to life in and among humans.

Long after humans domesticated dogs, they domesticated grain, and with grain came cities, granaries, and trash; and with those, rats, mice, and pigeons. The animals that could stand to be in close proximity with humans (but out of reach) thrived in the new niche–don’t underestimate just how many mice a bountiful harvest can feed:

One night's catch of 200,000 mice, 1917
One night’s catch of 200,000 mice, Australia, 1917 [source]
From a more recent account:

First to the mouse plague which has invaded three states and damaged hundreds of thousands of hectares of crops. The rodents may be a familiar pest for farmers but the volume of vermin visible across parts of WA, Victoria and SA hasn’t been seen in more than 15 years. …

CHERYL WILLIAMS, BAYVIEW STREAKY BAY SA: I reckon the other morning I would have got two bucketfuls and there would have been near enough to 2,000 in it because it was piled high.  … I had them in the house earlier on and they were climbing the walls and on the furniture. Just everywhere. On the beds, gives me the willies. I’ve had enough of it. I can hardly stand it. …

ALLAN WILLIAMS, BAYVIEW STREAKY BAY SA: … We’ve been taking out 20 to 40 litres every day for the last 100 days which that’s 2,000-odd litres of mice which is – I’ve never seen that amount of mice in me life. …

LEON WILLIAMS: You come out here at night time and it’s just literally a moving mass of mice. By the millions.

Mice and rats are interesting in and of themselves, but I will have to discuss them later. For now, let’s just say they were soon followed by an opportunistic predator:


Early cats probably moved into human settlements to hunt for rodents, and after a while, humans decided this was a useful behavior. Even today, many “pet” cats are expected to earn their keep, catching the mice in and around their homes–unlike the average dog.

(Reports of Medieval Europeans massacring cats are probably overstated–the famous “Cat Massacre” was actually an anti-aristocrat French mob murdering noble pets.)

While dogs have diverged significantly from wolves, the average house cat still looks quite similar to its wild relatives:

African wildcat, ancestor of the domestic cat
African wildcat, ancestor of the domestic cat

Distinct breeds of cats–including most if not all of the more unusual looking ones–are extremely recent, perhaps less than 200 years old, but domestic cats do differ from wild ones in several important ways. They are smaller, lighter, and they meow.

Interestingly, adult wolves do not bark and adult wildcats do not meow. Kittens meow at their mothers, and cats meow at their people, not each other. These are neotenous traits–baby behavior. Dogs will always be wolf pups, never adults, and a cat is always part kitten.

I shall leave you with a bit of light verse, from 9th century Ireland:

The scholar and his cat, Pangur Bán

I and Pangur Ban my cat,
‘Tis a like task we are at:
Hunting mice is his delight,
Hunting words I sit all night.

Better far than praise of men
‘Tis to sit with book and pen;
Pangur bears me no ill-will,
He too plies his simple skill.

‘Tis a merry task to see
At our tasks how glad are we,
When at home we sit and find
Entertainment to our mind.

Oftentimes a mouse will stray
In the hero Pangur’s way;
Oftentimes my keen thought set
Takes a meaning in its net.

‘Gainst the wall he sets his eye
Full and fierce and sharp and sly;
‘Gainst the wall of knowledge I
All my little wisdom try.

When a mouse darts from its den,
O how glad is Pangur then!
O what gladness do I prove
When I solve the doubts I love!

So in peace our task we ply,
Pangur Ban, my cat, and I;
In our arts we find our bliss,
I have mine and he has his.

Practice every day has made
Pangur perfect in his trade;
I get wisdom day and night
Turning darkness into light.

Why are people so keen on pets?

The Lady with an Ermine
The Lady with an Ermine

Don’t get me wrong. I like animals; I just don’t like them in my house. Every time I petsit for friends with cats, I am reminded of why I don’t own cats: scooping feces is repulsive (and don’t get me started on toxoplasma Gondii!) Dogs are marginally better, in that the homes of dog owners don’t always smell of feces, but unfortunately they often smell of dog.

For this post, I am defining “pet” as animals that people keep solely for companionship. Animals kept because they do useful things or materially benefit their owners, like seeing eye dogs, egg-laying chickens, mouse-hunting cats, race horses, or dancing bears are not “pets.” Medical “therapy animals” are basically pets. It makes plenty of sense for people to keep around work animals, but pets seem to be kept around simply for the enjoyment of their company.

According to Wikipedia, Americans own approximately 94 million cats, 78 million dogs, 172 million fish, and 45 million small mammals, fish, reptiles, etc. (Though of course some of these are “useful” animals that I wouldn’t count.) This comes out to about 4x as many pets as children, concentrated in 60% of the households (most pet owners have more than one.)

Pets cost quite a bit of money–the average small dog costs about $7,000 to $13,000 over its 14 year lifespan; the average large dog costs $6,000 to $8,000 over its much shorter 8 year lifespan. [source] (Note that it is cheaper per year to own a small dog; the lower lifetime cost is due entirely to their shorter lifespans.) Cats cost about the same as dogs–people don’t spend much on “outdoor” cats, but “indoor” cats cost about $9,000 to $11,000 over their lifetimes.

Just making some rough estimates, I’d say it looks people spend $700 per year per dog or cat, which comes out to about 120 billion dollars per year. That’s a lot of money! (And this doesn’t count the expenses incurred by shelters and animal control agencies to take care of the excess pets people don’t want.)

Americans are probably exception in the number of pets they have. According to Wikipedia, 46% of the world’s pet dog population lives in the US. (By contrast, only 4.4% of the world’s human population lives in the US.) The ratio gets even more skewed if we break it down by race–63% of America’s whites own pets, versus only 49% of the non-whites. [source]

However, other countries similar to the US don’t seem as keen on pets: the %pets/%people ratio for the US is 10.5, for Canada 7.5, and for Britain, 5.8. This might have to do with factors like Britain being a more crowded country where people have less space for pets, or with the Wikipedia data being inaccurate. Either way, I think it’s safe to say that pets are very characteristically American, and especially a white American thing.

One theory about why people own so many pets is that they’re substitute children/companions/friends for lonely people who don’t have kids/spouses/friends, perhaps as a side effect of our highly atomized culture. I came into this post expecting to confirm this, but it looks like Crazy Cat Ladies are actually a relatively small percent of the overall pet-owning population.

According to Gallop, 50% of married people own a dog, and 33% own a cat (some people own both.) By contrast, only 37% of unmarried people own dogs and only 25% own cats. People with children under 18 are more likely to own pets than people without. And people from the “East” are less likely to own pets than people from the “West.” (Interestingly, “westerners” are disproportionately more likely to own cats.)

So it looks to me like most pet ownership is actually motivated by the idea that kids should have pets, with pets more common in suburban or rural areas where they have more room to run around. This is probably particularly so for cats, who are probably more likely to be “outdoor” pets or mouse-catching farm cats in rural areas (ie, the “West.”)

There is an extensive belief–perhaps folk belief–that pet ownership is good for people. Gallop found that 60% of people believe that pet owners lead more satisfying lives than non-pet owners; numerous studies claim that pet ownership–or even just occasional interaction–makes people healthier. There even exists an “animal therapy” industry. Unfortunately, the studies on the subject look rather unreliable–the ones about pet ownership are confounded by healthier people being more likely to have pets in the first place, for example.

And yet, there’s something about the notion that I find appealing; something about playing with happy puppies or petting a bunny that I find downright pleasant. Maybe it’s something as simple as animals being nice and therefore making people happy.

It’s getting late, so I’ll continue this tomorrow.

Cats are Cuckoos

Cats win at Evolution,” (from Cave People and Stuff,) is a great article about the evolution of cats from primate-predator to primate-parasite.

A quote:

“The domestic cat – aka Felis catus or Felis silvestris catus – is the same size as a human infant.  Its mew sounds very similar to the cry of a newborn human baby.  It has a round face with big eyes, like a human infant.  The domestic cat has gone down the same evolutionary route as the cuckoo, only much further.  Its entire life-cycle involves imitating baby humans and being coddled, fed and protected as though it were a human infant.”

Fabulous post. Go read it all.