Are humans the only animal to drink milk from other species?

Are humans the only animal to drink milk from other species?
09 January 2011



Are humans the only animal to drink milk from other species?


Diana - Most of us will have seen our pets and various garden wildlife taking advantage of a source of cow's milk on occasion. But are we the only ones to drink it habitually?

Oliver - I'm Oliver Craig and I work at University of York in the Department of Archaeology.

In fact, we are - well at least, we are when we're adults. All juvenile animals can drink milk and that's because they have the enzyme lactase to digest the milk sugars. But the genome that makes the enzyme gets switched off when they get to a certain age, so as adults, they can't drink it. Most humans in fact can't drink milk as adults and there's only a very small fraction of the world's population who can. What's really interesting of course is that those people live in a very geographically restricted area, i.e., Northwest Europe and some parts of Africa. So it's a really interesting question as to why only a certain part of the population can drink milk.

If you're lactose intolerant, you don't possess this enzyme lactase. So basically, the lactose that's in the milk doesn't get digested. It's a disaccharide and it passes straight through the gut and goes into the colon, and it can cause all sorts of unpleasantness, including what's generally quoted as some kind of explosive diarrhoea, and is a really, really nasty condition if you can't actually break these sugars down. But it also causes problems with water retention and all sorts of other problems as well. So really very ill, bad stomach and not actually been able to digest the sugar itself. So at some point in our history, it was a selective advantage for people in Northwest Europe at least to be able to drink milk.

Diana - But does being lactose intolerant really put you to selective disadvantage?

Oliver - Well, you wouldn't have thought it would really, would you? It's not going to impact on your daily life massively. It's only going to be selective disadvantage if there's a real advantage in being able to drink milk, fresh milk. It comes back to the question then, why is being able to drink milk such a selective advantage? The answer is that we really don't know and that's what we're trying to research and find out. The first thing that we need to do is find out when or at what point in our history did that need to drink milk actually occur?

Diana - As far as we know, humans are the only animals to drink another species milk regularly, but only a small proportion of humans have the lactase enzyme. Cats and dogs are often seen taking delight in a serving of milk, though I'd rather not consider the consequences. An excellent find on our forum came from Jackass Penguin who cited the Red Billed Oxpecker, a bird that can perch on the udders of an Impala and drink its milk. Elsewhere, in Isla de Guadalupe, feral cats, seagulls, and sheathbills have been observed stealing the milk directly from the teats of elephant seals. So perhaps milk stealing does happen a little more than we currently know.


What in the world are you talking about?
Most adults everywhere can drink milk without any issues. In fact I drink milk every single day and I know lots of adults that do too.

99% of people I know drink cows milk. No issue. Your research/study has a closed view. It is a waste of time as you will steer the results whatever they are to support your mindset.

If you want the science about why not drinking milk, and not just an opinion, watch How Not to Die on Amazon Prime. Has all the science!

Ants milk aphids.

Ants stroke aphids to encourage them to defaecate some sugary water, which the ants drink. In return the ants protect their aphid "brood". But the material the aphids produce is not milk, per-se. Good thought though!

In my comment "How long have primates been drinking milk of another species ?" I erred in omitting the words "cows milk" from the first sentence. This site provides no way to edit out an error after inadvertently hitting the post button. ... sorry.

I read everywhere that adult humans have been drinking for only about 8,000 years. I question that. Primates such as Australopithecus and Ramapithecus had to be sufficiently intelligent (way before Homo Sapiens) to drink and continue drinking milk , even from other species, into adulthood, just as some lower primates do today. I do not accept the common "fact" that humans are today the only species that continues drinking milk from another species into adulthood. Primates were good observers and intelligent experimentors way before 50,000 years ago.

I live in South Africa and have a friend who is a cattle farmer and it's apparently quite common for adult baboons to come and deal milk directly from the cows udders, and will sometimes bite the cow if they do not cooperate.

I'd heard this sort of claim before but had always dismissed it as people exaggerating; nice to know it's true! 

Didn’t you finish reading? It’s not completely true

This is one of the dumbest questions ever. If it was tasty (yes) and nutritious (yes) other animals would absolutely drink it if they could figure out how to milk it! Unfortunately for the carnivores they can’t help but kill the lactating animal first but I guarantee you they don’t spit out the milk. Bet you can find a YouTube video of a cat who’s figured out how to milk a cow or goat. Going to search that now.

That’s one of the arguments that I’ve always made when I had a discussion with vegans.

This is all absurd. You can't compare humans to animals. Animals will usually eat to live. I had a mature pony that regularly would drink a gallon or two of milk if so offered. We - on the farm - had milk to feed to cats. Cats who chose to drink the milk offered regardless of their age. Can an animal other than perhaps a chimpanzee or ape choose to search out Milk to drink on a regular basis? Of course not. Everyone has an opinion of what is "natural" . Its just crazy. On the great lakes Germophobes will drink tap water but not drink out of Lake Erie. Duh, you are drinking lake erie water that has just been filtered through a huge pile of rocks and then have bleach added. If you only really knew you might go crazy. How many other foods are there that are not generally available to animals? Oats? soybeans? tofu? wheat? lettuce?
If there was a trough that regularly had fresh milk in it. And there was availability of other foods. I believe that many animals would knowingly choose to drink the milk. Back to the "they would if they could" story. Such as certain animals make their home in a place where a food source is plentiful. Enough said.....

Ummm humans *are* animals.....

Humans are humans. Animals are animals.

If you want to drink milk, drink milk. if you don't then don't. don't force your beliefs on others. PS-growing hogs can be fed excess skim milk, and thrive on same in a properly balanced ration

If animals could raise cows like vegetables for their milk and meat they would.
No i dont think they would. As the intelligent species given the power and the responsibility to rule over other living creatures we are going to be held accountable for how we treat those beings powerless to defend themselves from our rampant consumerism and gluttony.
You dont need a science degree. Common sense should point out the blazing red flags that something is wrong. We are literally destroying the ozone layer with cow flatulence while we run other species into total extinction. Our bodies dont need calf food as adults and actively reject it. If nature isnt enough reason you can count on humans to jump in the mix and make it worse with growth hormones and inhumane breeding conditions that breed bacteria and disease just as well because assembly line production is not suitable for probably any product meant for human consumption let alone sentient creatures born and bred for slaughter. Anytime profit takes precendence over conscience there will be fallout and it taints anyone who touches it. Simply a matter of natural law.

God gave us dominion over all the animals. And more than once in the Bible, he advised is to kill and eat. You must be an idiot to think animals are as worthy as we humans. God didn’t send His Son to die for the sins of animals—for they have no will to decide to sin against him. Only we humans have that privilege—or the privilege of being obedient to the Bible../

but this is a science site, not a church; please confine religion to bible classes and keep contributions here evidence-based. Thank you.

do you think bigfoot was on noah's arc?

Probably not- Probably couldn’t find them. But if there’s a complete list of what animals were on the arc you could refer to that. I haven’t read it but i doubt the Bible discusses cryptids.

Spare us the bullshit about God. This is all man made assumptions to justify not using common sense.

Small children are given apple juice to produce bowl movements because their bodies lack Sucrase which is the enzyme that breaks down sucrose (natural fruit sugar) but whole apples don’t produce the same effect because pasteurization kills the enzymes. The same thing can be said about milk. Raw milk naturally contains lactase enzymes to digest lactose but pasteurization kills the enzymes. Whole apples are healthy and so is whole milk but pasteurized prossessed food are not.

When making claims like this, you must support your arguments with actual evidence rather than hand-wavy science mumbo jumbo. Do you have any published evidence to support the claims you have made above? If not, and until such information is supplied, I'd urge everyone reading the comment above to disregard it...

I guess everyone better disregard my previous message to Z then because I've got no actual evidence for my claims either, but I'm pretty certain it's illegal to allow anyone to kill your only begotten son.

God knew his son would live.

Okay, let's unpack this.
First of all, natural fruit sugar is called fructose. It's a 5 carbon sugar and we possess enzymatic pathways to turn it into useful blood sugar, glucose, which is a 6 carbon sugar. Sucrose is a disaccaride made up of a glucose and a fructose joined together. Certain plants make sucrose like sugar cane or beets, but apples don't.
Even if they did, the enzyme that break sucrose into glucose and fructose would not be present in the apple (this applies for the milk too); if it was, it would react with all the sucrose before you've even eaten it. That's what it does. And if that's the case, denaturing the enzyme won't matter because all the sucrose has already been converted into glucose. Besides, the acidic conditions and proteolic enzymes in the stomach means almost all dietary enzymes are denatured immediately.
Pasteurization just makes sense. Milk, especially from heavy commercial sources, can have traces of blood or even pus in it from the users. It destroys all the pathogens and makes it safe to drink. The only dietary elements in milk that would be affected would be the proteins/enzymes which would unravel (denature), but as I said, that happens when they hit the pH 2 environment of the stomach.

Chemistry is hard. It's easy to get mixed up. But if you want real information you can trust, you have to go back to fundamentals.

Are you telling me that if a lion eats a lactating gazelle it doesn't drink the milk? If a polar bear captures a lactating seal it spits it out? This "only humans drink the milk of another species" or "only humans drink milk as adults" crap has to stop. Maybe only humans cultivate another animal to drink the milk, but most animals don't cultivate vegetables either. This argument is inane and you should more forcefully put it down.

I agree. If other animals could they would.

This is the most disgusting s**t I’ve ever heard!!!! Those of you arguing, would your gross ass walk up to a cow, put its teet in your mouth and start guzzling? You’ve just become desensitized to it cause you think milk comes from a carton... really spend some time thinking of how gross it is to just walk up to any other animal and do that!

If i was raised on raw milk. I wouldnt necessarily put the nip in my mouth (cuz that is just weird) but i would certainly squirt it into a bucket or bowl or somthung and then drink it, thou i prefer my milk cold. So assumong someobe says these thibgs just cuz u assume they wouldnt do that is stupid... Plenty of ppl grow up on fars that drink milk fresh from the cow (raw milk) a.k.a my Mom, thet have no problem squieting some milk in a xonta8ner if they need it straight from the cow. What do u think ppl first did when we first started drinking from cows, shoot im sure that if they had no container they woukd squirt it staight into their mouths.

I was brought up on a farm we raised goats we were brought up on goat's milk but also cow's milk we would do haying on a hot day and as we go by The milk Barn with jump off run up to the big silver canister and drink some ice cold milk fresh from the cow. But I love ice cold milk

I was raised upon a dairy farm, while we never used to send the calves away for veal, one of the things we did was take a 2 pint milk tin (for the house), fill it with fresh milk, as in about 10 minutes old. Take it to my mum, back at the house. She would pour it through some gauze/linen, and then we could drink it.
On another note, yes, other animals have been documented in drinking the milk of other species, if I knew how to I'd put a link up to prove it. Primates have been noted to, definitely.

If you don’t like the idea of milk, don’t drink it...

Animals would do this on rare occasions as it would benefit there survival. Food is becoming more scarce due to human activities so they need to use these resources to be alive. Humans do not need cows milk to SURVIVE.They actually hinder our survival in many ways, research the negative effects of milk its definitely worth having a look. That is where the difference is. We are lactose intolerant for a reason.

And your evidence in support of the unqualified assertions that you have made here is...?

Did you know that humans are born sucrose intolerant? But you wouldn’t think twice about giving your small child fruit juice. Whole fruits contain sucrase enzymes to digest sucrose, but the pasteurisation prosess kills the enzymes making juice as intolerant as pasteurised milk. Raw milk naturally contains lactase enzymes to digest lactose, but pasteurisation kills the enzymes.

Please support your claims with corroborating evidence i.e. links to published, peer-reviewed sources that categorically show that milk cotains lactases.

Why I am sceptical is that, if these lactases are functional, why is there any lactose left in the milk? They would have degraded it. And moreover, when it goes through the human I tract, the low pH in the stomach will denature the enzyme every bit as effectively as the high temperature of pasteurisation.

So I don't believe you... but I'm willing to consider evidence that you are right, if you have any...

Well, milk might not have lactase enzyme but there are in fact bacteria that digest the lactose and convert it into things like lactic acid, as well as acetic acid, the main component in the sour taste of vinegar, which gives soured and aged dairy products that tangy flavor. The more lactose is converted the better it is for people who have lactose intolerance. Some products, like swiss cheese, don't contain any lactose at all when aged properly. So there might not be lactase in raw milk but there are definitely reasons raw milk products or re-cultured milk products are better.

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