Have you ever stopped to think about smells? Some smells are just delightful, like freshly baked bread or perhaps cookies warm from the oven. You know, that lovely scent after it rains? People vote on these good smells, and they are very popular. But then, there are those other smells. The ones that make your nose wrinkle, and your stomach turn, in a way. It's almost like a universal agreement that some things just do not smell good at all.

We experience many different substances and chemicals in our daily lives. Some of these things smell quite pleasant, but others, they just do not. It is interesting, too, how some compounds give off a clear scent, while others have no smell we can detect. So, what makes some things smell so incredibly bad? What takes a scent from simply unpleasant to truly awful?

This article explores some of the most unforgettable and truly terrible odors found across our planet, and even beyond it. We will look at plants, animals, man-made chemicals, and even a planet that holds a rather stinky secret. It is quite a journey for your nose, even if it is just in your imagination. You might be surprised at what tops the list of the world's worst smells.

Table of Contents

• Plants with a Powerful Punch
  • The Corpse Flower
  • Rafflesia Arnoldii
• Animals That Make a Stink
  • The Striped Skunk
  • The Hoazin Bird
  • The Shore Earwig
  • Millipedes
• Chemicals and Compounds of Odor
  • Mercaptans: The Smell of Gas
  • Rotten Fish: A Penetrating Smell
• Unpleasant Everyday Odors
  • Sewage and Faecal Matter
  • Fatbergs in the Sewers
  • Stinky Foods That Taste Good
• A Smelly Planet Far Away
• Frequently Asked Questions

Plants with a Powerful Punch

Some of the most infamous bad smells come from the plant kingdom, it is true. These plants often use their strong scents for a particular purpose, like attracting specific pollinators. They are, in a way, designed to smell bad to us. They can be quite surprising in their ability to produce such awful smells.

The Corpse Flower

The plant known as Amorphophallus titanum, which people call the corpse flower, is widely believed to be the smelliest plant on earth. This plant is found in the rainforests and limestone hills of western Sumatra. When it blooms, it really lets out a strong smell. That smell is very much like rotting flesh, apparently. It is a smell that many find completely unbearable. People often travel just to experience this smell, which is quite something. It blooms rarely, making the event even more special, and smelly. The smell helps it attract insects that usually visit dead animals, so it is a clever trick for the plant.

Rafflesia Arnoldii

Another contender for the smelliest flower title is Rafflesia arnoldii. This flower is not only considered one of the smelliest in the world, but it is also the largest. It shares some of the same unpleasant characteristics as the corpse flower, like its very strong odor. It is found in similar rainforest environments. This flower also uses its strong smell to attract insects for pollination. It is a pretty amazing sight to see, too, with its huge petals. But you might want to hold your nose when you get close, in some respects.

Animals That Make a Stink

The animal world has its share of creatures that produce truly awful odors. These smells are often a defense mechanism, a way to keep predators away. It is their way of saying, "Stay away!" You know, a bit like a warning sign. These animals have evolved some pretty effective ways to deter threats, which is actually quite clever.

The Striped Skunk

When we talk about smelly mammals, the striped skunk is almost always at the top of the list. Its stinking spray is very well known, of course. A human nose can detect this spray if it is carried by the wind a mile (1.6 km) away! That is how powerful its scent is. The skunk uses this spray when it feels threatened, and it is a very effective deterrent. No one wants to get sprayed by a skunk, that is for sure. It is a smell that sticks around for a long time, too, which is part of its effectiveness.

The Hoazin Bird

While the striped skunk is the smelliest mammal, the smelliest bird is a close contender. This bird, also known as Opisthocomus hoazin, comes from the Amazon Delta. It is so stinky that humans only hunt it when they are in dire need of food. Its foul smell comes from its unique digestive system, which ferments vegetation in its foregut. This process creates a very strong, musky odor, apparently. It is a smell that makes it unappealing to most predators, which is probably a good thing for the bird. You know, it is a survival strategy.

The Shore Earwig

Even small bugs can produce powerful odors. The shore earwig is one such creature. This bug squirts out a smelly substance to fight off predators. It is a tiny creature, but it has a big defense mechanism. This substance is designed to be very unpleasant, to make any attacker think twice. It is pretty amazing how even the smallest animals have ways to protect themselves, in a way.

Millipedes

Millipedes also have a smelly defense. When these creatures feel they are in danger, they curl up into a spiral. Some species then release a foul-smelling liquid. This liquid is often made of cyanide compounds, which are not only smelly but can also be toxic to smaller predators. It is a pretty effective way to tell potential threats to back off. You know, a clear warning. This chemical defense is another example of how animals use smell for survival.

Chemicals and Compounds of Odor

Beyond living things, there are specific chemical compounds that are known for their incredibly bad smells. Some of these are naturally occurring, while others are actually made by people. Scientists learn about the worst-smelling small molecules and larger chemical compounds. This includes chemicals man has made purely so they would smell bad, which is quite a thought.

Mercaptans: The Smell of Gas

Have you ever said, "I smell gas" inside your house? You are really smelling mercaptans. Natural gas itself has no odor, so ethyl mercaptan is added to it to make gas leaks easier to detect. This compound has an odor detection threshold of just 1 or 2 parts per billion molecules of air. That means in billions of molecules of air, we can detect just a few mercaptan molecules. It is an incredibly potent smell, and for a good reason, too. It saves lives by warning us of danger, which is pretty important. There are substances smellier than gasoline, and mercaptan is one of them, certainly.

Rotten Fish: A Penetrating Smell

The smell of rotten fish is universally recognized as one of the most penetrating and unpleasant odors that exist. This smell comes from the breakdown of proteins and fats by bacteria. Compounds like trimethylamine are responsible for this particular stink. It is a smell that seems to cling to everything and is very hard to get rid of, you know. It is a very distinct and powerful odor, and most people find it truly awful. This is a smell that, once you smell it, you probably won't forget it.

Unpleasant Everyday Odors

Some of the worst smells are ones we might encounter in our daily lives, even if we wish we did not. These are smells that are pretty much universally disliked. They are just part of life, in some respects, but they are certainly not pleasant. These smells are often tied to natural processes or things we create.

Sewage and Faecal Matter

Unsurprisingly, sewage and faecal matter are ranked very highly as universally appalling odors that can be encountered. This smell is a complex mix of many different volatile compounds produced by bacteria breaking down organic waste. It is a smell that most people find incredibly unpleasant, and for good reason. It is often associated with unsanitary conditions, which is why it triggers such a strong negative reaction in us. It is a basic, primal dislike of the smell, actually.

Fatbergs in the Sewers

On top of being incredibly unpleasant to smell, the bacteria that are breaking down sewage can actually cause other problems. In addition to smelling awful due to bacteria breakdown, you can also get build-ups known as ‘fatbergs’ in the sewers. These fatbergs are huge, congealed masses of fats, oils, greases, and non-biodegradable items like wet wipes. They block sewers and cause major issues. The smell from a fatberg is, apparently, even worse than regular sewage, because of the concentrated decomposition happening within them. It is a very serious problem for city infrastructure, too.

Stinky Foods That Taste Good

It is funny how some foods can smell quite bad but taste absolutely delicious. They may taste good, but a list of foods below have a bad rap for being among the stinkiest in the world. Think about pungent blue varieties of cheese, like Roquefort and Cabrales. These cheeses have very aromatic, strong smells due to the molds and bacteria used in their production. Yet, many people absolutely love to eat them. It is a strange contrast, isn't it? The smell can be off-putting to some, but the flavor is highly prized by others, which is quite interesting.

A Smelly Planet Far Away

The quest for the smelliest thing does not stop on Earth. Yes, there is a smelliest planet, and it is Uranus. Scientists discovered that Uranus smells like rotten eggs because its atmosphere contains a gas named hydrogen sulfide. This gas is what gives rotten eggs their distinctive, awful smell. So, if you were to visit Uranus, which is not possible right now, it would be one of the smelliest places to visit in the solar system. It is pretty amazing to think that a whole planet can smell so bad, in a way. This discovery tells us a lot about the planet's composition, too.

Frequently Asked Questions

What is considered the worst smell on Earth?

Many things compete for the title of the worst smell on Earth. However, the corpse flower, known as Amorphophallus titanum, is widely believed to be the smelliest plant. Its smell is often compared to rotting flesh. Also, things like sewage and rotten fish are universally recognized as extremely foul odors.

What is the smelliest animal in the world?

The striped skunk is considered the smelliest mammal due to its powerful, stinking spray. A human nose can detect this spray from a mile away if the wind is right. The hoazin bird from the Amazon Delta is a very close contender for the smelliest bird, known for its strong, musky odor.

What chemical is known for having a very bad smell?

Ethyl mercaptan is a chemical compound known for its incredibly strong and unpleasant smell. It is added to natural gas, which is odorless, to make gas leaks detectable. Its odor can be sensed at extremely low concentrations, meaning just a tiny bit of it can make a whole area smell very bad.

Learn more about unusual facts on our site. You can also explore more about the science of smell.