I tried to make the topic interesting ;)

I hear that rotting human flesh smells much worse than rotting animal flesh. Is there any truth to this? Why is that?

I also hear stories of human feces killing plants (such as grass). What causes human feces to kill grass, while manure replenishes it?

Just a 'Intro to Biology' college student here, be nice ;)

Feces from almost any animal, in large enough amounts, will kill grass. Animals that have high levels of nitrogen in their feces, like dogs or humans, will kill grass because the levels are toxic.
Where cows defecate on grass, the manure will actually smother grass, since the manure is mostly tough-to-digest cellulose, which is the major ingredient in plant.

Humans have much more variety to their diets, where animals eat almost the same thing every day. Maybe that has something to do with the bad smell?

There may be several things as to why shit smells bad. Biologically, it's toxic to us, so it'd make sense if it was really gross, because it's dangerous. It's also dirty– full of harmful microbes and pathogens and parasites.
Smelling like shit is both a sign of being dirty and potentially infectious.
There's probably a cultural thing associated with that, where smelling like shit's a sign of barbarism or lack of civility.

There's probably a cultural thing associated with that, where smelling like shit's a sign of barbarism or lack of civility.

...and the fact that it is physically repulsive. Cultural thing or not bad smell is great deterent.

Sarge,
Nothing smells intrinsically bad. Flies love the smell of shit. I'm just postulating about why it smells bad. Just as eating cow intestine, or rat, or dog may sound repulsive to you, fecal matter's repugnance to us may be much stronger than it once was.

Dogs eat their own fecal matter, I'd like to see someone explain THAT.

Because its good?

Seriously - you do not know how much the generation previous to sanitary reforms lived in the fecal matter of their cohorts. Shit is not actually that much to be afraid of - especially your own. The most it will tend to contain is bacteria that are already living in the flora of your intestines. However, when humans moved into urban (and even suburban) situations, that drastically increased the need for sanitary conditions for sewage - increasing the probability of encountering a dangerous pathogen.

Because the population density for dogs is much, much lower than that for humans, the likelihood that they will encounter a threatening bacterium from other dogs' feces is very low. In the high population densities that humans now live, it is not only likely but inevitable despite the omnipresence of antibiotics. We are all just waiting for the airborne transmissable phase of a virus like HIV (or Ebola, or any maladaptive virus).

But more importantly, why do we smell worse than a dead animal after death?

I ask this because we were talking about the black plague, and someone brought up that humans smell worse dead than animals. Being the aspiring biologist that I try to be, I set course to find the cause of this!

Thanks for the help.

Well the problem is that a "smell" is subjective and therefore cannot be measured quantitatively. So perhaps one person thought that the human smelled much worse, whereas another thinks the animal smells worse. I am by no means a biologist and have limited knowledge on the subject but it still seems to me that what i said should be valid. Is there a general consensus that humans smell worse after death?

I hardly believe there is one. Rotten flesh essentially smells the same, especially as the main components (tissues etc.) are not significantly different between humans and, say, pigs.
The bad smell from feces is heavily influenced by the diet and the bacterial composition in the respective guts.

The question should be, why does the smell of rotting human flesh smell worse to _humans_? Perhaps because something that kills one human might kill another human so evolution has programmed a strong olfactory aversion? Just a thought.

Well could be, though I sincerely doubt that it is the case. Rotting pork smells roughly like human (though with all the disinfectants it is sometimes hard to tell), rotting fish is really awful, though distinctly different and so on.

Primates do have different amounts of bacteria present than other species. Most noticably in our mouths. If you get bitten by a human you almost always get a nasty infection. If you get bitten by a dog you get nothing. If you want to see how bad we smell without all our hygeine go to the zoo. The monkeys always smell the worst and thats basically what were closest to.

But I bet the monkeys dont think they smell.

If we sat around our own poo all the time wouldn't we become used to the smell?

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The smell of excrement is very important to animals. The NGO in their noses can detect lots of infomation about that animal be the waste.

For example, they can tell if that animal is related to itself and helps avoid any in-breeding that could occur if it mated which would reduce the gene pool.

Any decomposing of any animal is going to smell bad to us as we are told by the smell that it is dangerous. Most animals around us are smaller, in the UK. Such as mice and dogs, cats and other pets. We are much larger and the space for bacterium to grow is much bigger. You would have to go to a farm and smell a dead decomposing horse or cow to compare the smell.

Thyis thread stinks like I cant even imagine :cool:

Frisbinator:
Dogs eat their own fecal matter, I'd like to see someone explain THAT.
My theory, insecurity.
I've noticed that among all dogs, meaning a ton of neighbour's and my own, its the females and beta males that roll in the shit.

So it would be something like a human smearing itself in cosmetics to enchace its own beauty and hiking its chance for acceptance.
Therefore, the insecure canine will smear in feces to enchace not its beauty but smell, hiking its chance at acceptance?


On topic:
Remeber the baby years.
We played in our own shit, I even ate some.

Point benig that this repulsion to feces is learned.

I think eating your own shit is one of those past-times you experience and then a second later think, that was a shit idea.

I read somewhere that dogs' intestines are quite short and the bacteria in it doesn't have enough time to do whatever it does as the food passes through it, so they eat feaces to bolster the bacteria count, or something like that anyway.

I think the reason that dogs have a propensity to roll around in shit or anything that smells foul is to give themselves a smelly sort of camouflage, so that downwind so to speak, a predator would smell the shit and not the dog.

Tablaridim:
I think the reason that dogs have a propensity to roll around in shit or anything that smells foul is to give themselves a smelly sort of camouflage, so that downwind so to speak, a predator would smell the shit and not the dog
Camoflauge from what?

Lions?
Wolves are seen smeareing themselves right before they enter their pack, with their tails tucked but stinking to hell of hot shit.
The others will smell him and rarely bother him.
Is this camoflauge?
It looks more like a gift offering or a bus pass.

If it is camoflauge from predators, then why do wolves do it?

Ok, maybe it's not camouflage from predators but camouflage from prey. They want to cover their own odours so their prey won't be alarmed by their scent. This way they
can sneak up on their prey and have a better chance of making a kill.

Dogs eat their own fecal matter, I'd like to see someone explain THAT

As explained to me by a biology teacher, the dog's digestive system is not efficient enough to get all nutrients out of the feces the first time through, so eating feces is just a way to gather nutrients.

As explained to me by a biology teacher, the dog's digestive system is not efficient enough to get all nutrients out of the feces the first time through, so eating feces is just a way to gather nutrients.
Soo....he'll eat nutrient deficient feces from other dogs to supplement his nutrient deficiency?

That's like taking arsenic to cure hemlock.

Tableredim:
Ok, maybe it's not camouflage from predators but camouflage from prey. They want to cover their own odours so their prey won't be alarmed by their scent. This way they
can sneak up on their prey and have a better chance of making a kill.
That still does not make sense.

A key point to camouflage is to remain hidden. The smell of blood on a tigress would certainly give her away.
The smell of blood or feces on wolves would do the same thing.
So why say camouflage?

The main reason why felines, for example, hide their waste is too keep their smell hidden and by doing so, made untraceable back to them.
To say that a dog or a wolf rolls in feces for camaflouge is to say he puts bells on and sings when his goal is to hide.

Something else I've noticed in the female dogs and the weak beta males (shit thou not): they eat dirt.
I've never seen the alpha eat dirt or roll in shit.
But all the females and betas do.

They dig a hole in ground that is wet, preferably clay, and scratch at the stuff with their teeth to eat it.
So, so far what I've noticed in corprophagia:

Roll in shit.
Eat dirt.

Huh?! I cannot connect the two. Why?

We can land a man on the moon, but not cure common cold or explain Fido rolling in shit.
Insanities.

To a dog, all feces are is a pile of bacteria

Dogs eat shit. No, it's not because their feaces don't contain enough nutrients, but because their feaces are only partly digested due to their short gut, so, by eating their own shit they are able to absorb more nutrients by the more easily digestible dung, it probably tastes good too.

They roll around in shit or anything which smells really bad actually, so that as they creep up on their prey downwind their own doggie smell is 'camouflaged'. The prey can smell the shit or the dead animal that the dog rolled around in and will not get unduly worried. Of course, given that this is common pactice amongst wolves/dogs, it does make one wonder why the prey hasn't cottoned on to the idea that dog/wolf = shit/obnoxious smell. :confused:

I know all this is true because I researched it on the internet:rolleyes:, but seriously, it does make sense to me. :m:

Dogs eat shit. No, it's not because their feaces don't contain enough nutrients, but because their feaces are only partly digested due to their short gut, so, by eating their own shit they are able to absorb more nutrients by the more easily digestible dung, it probably tastes good too.

They roll around in shit or anything which smells really bad actually, so that as they creep up on their prey downwind their own doggie smell is 'camouflaged'. The prey can smell the shit or the dead animal that the dog rolled around in and will not get unduly worried. Of course, given that this is common pactice amongst wolves/dogs, it does make one wonder why the prey hasn't cottoned on to the idea that dog/wolf = shit/obnoxious smell. :confused:

I know all this is true because I researched it on the internet:rolleyes:, but seriously, it does make sense to me. :m:

Is that why Werewolves smell so bad at parties and family gatherings?

Novacane