Buzz
Smells play an important role for both animals and plants, acting as vital signals to convey information—whether it's a warning or an indication of mating behavior. Certain chemicals also function as protective mechanisms, emitting strong odors to deter predators.
10. Grizzly Bears Can Detect Scents From 30 Kilometers (18 Miles) Away
Grizzly bears, among the most formidable creatures in North America, sometimes struggle to adjust to the growing human presence in their territories. This can lead to the bears attacking humans and causing damage to property.
Despite having limited eyesight, these highly intelligent grizzly bears are among the top predators. They possess several traits that aid in their survival, including their exceptionally sensitive noses.
A grizzly's nose is lined with honeycomb-like tissue within the nasal cavity. This sense of smell is thought to be up to 100,000 times stronger than that of humans, enabling the bears to perform remarkable feats like sensing clams underground or detecting fish in water.
Grizzly bears can even smell things from as far as 30 kilometers (18 miles) away. This ability helps them scavenge kills from other animals, as they can intimidate the smaller creatures and easily claim their food.
In comparison, polar bears have the remarkable ability to detect seals from distances as far as 65 kilometers (40 miles).
9. Striped Polecats' Scents Can Be Detected From Up to 2 Kilometers (1 Mile) Away
The striped polecat, also known as the zorilla, operates largely under the radar on the African savanna compared to its more famous relative, the skunk. Nevertheless, this small creature deserves recognition for potentially being the smelliest animal on Earth.
Like the skunk, the striped polecat has specialized anal glands that emit a nauseating odor. It also possesses a set of muscles that allow it to direct this chemical spray at any potential threat.
The stench, which has been likened to the smell of rotten eggs or a gym locker, can be detected from up to 2 kilometers (1 mile) away. This eye-watering odor is caused by sulfur-based compounds known as mercaptans.
The polecat's secretions are not only foul-smelling but also taste unpleasant, which may further discourage potential predators. This defense mechanism, along with the polecat's ability to play dead when its scent fails, serves it well in avoiding danger.
8. Rats' Sniffing Patterns Are Influenced By The Odor
Research conducted at the University of Chicago has shown that rats, along with some other animals, can focus their sniffs. Their sniffing patterns adjust based on what they are trying to detect.
Scientists had long speculated that some animals possess this ability, much like how humans focus their vision. For rats, this specialized sniffing becomes essential when searching for food or evading threats.
In the study, when rats were searching for a specific chemical, they could distinguish whether the smell was stronger, weaker, or different. They would then adjust their sniffing intensity before selecting the correct container.
Despite the obstacles they encountered, the rats always managed to identify the right scent. The researchers also observed that intense odors had a stronger impact on the front of the rat’s nasal cavity, influencing how deeply the rat inhaled.
7. Moles Can Detect Scents in Stereo
The common mole uses both of its nostrils to triangulate the origin of a scent, enabling it to find the source within seconds. This ability is essential for moles, as they rely on their sense of smell for survival due to their blindness.
Until recently, scientists had believed that no mammal possessed this ability. Researchers are now eager to test whether animals that rely on their sense of smell, such as rats, dogs, and pigs, share this unique trait.
To test their theory about the moles’ abilities, researchers inserted straws into the animals' noses, which significantly slowed them down when they were searching for food.
When the straws were placed in each nostril and crossed, the moles would veer away from the food, proving they indeed smell in stereo. Sharks and ants are also known to have this ability.
6. Mosquitoes Can Detect You Better at Night
Mosquitoes, often considered one of humanity's greatest pests, are skilled hunters at night. Scientists may have finally discovered the reason: a chain of odorant-binding proteins (OBPs), which assist mosquitoes in detecting humans, accumulate in higher quantities during the night.
OBPs are thought to help transport molecules to the mosquito's olfactory receptors. Additionally, mosquitoes maintain their sensitivity to odors that do not require OBPs, as well as the proteins needed to detect those smells.
By sensing the odor of our bare skin and the carbon dioxide we exhale, mosquitoes can detect us from up to 30 meters (100 feet) away. Other insects, such as tsetse flies and cockroaches, also show enhanced olfactory abilities at night.
Like many creatures, mosquitoes follow daily rhythmic cycles. Researchers believe this newfound knowledge could aid in preventing the spread of malaria.
5. Sea Hares Make Their Predators Unable to Smell Them
Sea hares, slow-moving marine creatures vulnerable to predators, produce a unique secretion for defense. When threatened, they release a combination of purple ink and a sticky white substance called opaline.
For years, scientists struggled to understand how this defense mechanism protected sea hares. These creatures also possess a basic form of camouflage, which depends on the type of seaweed they consume and live within.
The sea hare’s chemical secretion disrupts a predator’s sense of smell by coating its antennae, allowing the hare to escape while the predator is distracted by the need to clean itself.
Thanks to this remarkable defense mechanism, sea hares face few predators, with the California spiny lobster being one of the rare exceptions. However, lobsters are often deceived by the sea hares' secretions and end up attempting to consume the ink instead. As a final line of defense, sea hares also possess toxins in their flesh.
4. Honeybees Have a Better Sense of Smell Than Dogs
Various organizations, including DARPA in the US and Inscentinel Ltd. in the UK, have trained honeybees to detect bombs and illegal drugs. Due to their exceptional olfactory abilities, honeybees are as effective, if not more so, than dogs typically used for such tasks.
Lured with sugar water as a reward, the bees are observed extending their proboscises upon detecting the target scent, whether it be a bomb component or an illegal substance.
Honeybees are not only easier and more affordable to train, but they also have the remarkable ability to detect almost any smell. While training a dog to be an effective sniffer can take months, a bee can learn to find contraband in just a few hours. Additionally, they can identify scents so faint that they are akin to a grain of salt in an Olympic-sized swimming pool.
3. Binturongs Have the Smell of Buttered Popcorn
Binturongs, also known as bearcats, have a strange mix of features, such as a cat's face, a bear's walk, and a prehensile tail nearly as long as their body.
A distant relative of the cat, binturongs belong to the lesser-known viverrid family. Among their odd traits is the secretion of a substance that has a strong buttered popcorn smell.
The secretion is most likely used to mark territory. This substance is released through their anal glands and seems to flow continuously from their behinds, much like a leaky faucet.
When marking their territory, they perform specialized dances. These dances typically involve dragging their rear ends across the branches and foliage that make up their home.
2. Brown Marmorated Stinkbugs Smell Like Cilantro
The brown marmorated stinkbug, a highly common insect with almost 300 different species, is found worldwide, much to the annoyance of those it encounters. The United States was overrun by these pests after they were inadvertently introduced via packing materials from China in the late 1990s.
These stinkbugs travel in large groups, causing extensive damage to crops by piercing the skins of fruits and vegetables. This results in billions of dollars worth of damage annually. However, brown marmorated stinkbugs also have a curious characteristic.
When crushed or injured, they emit an odor that closely resembles cilantro. Some people have also reported a scent akin to burned rubber. This smell can even transfer to fruit, which creates a significant issue with wine grapes.
1. Western Grey Kangaroos Smell Like Curry
Western grey kangaroos, one of the most abundant kangaroo species in Australia, possess a number of traits that distinguish them from other kangaroos. Notably, they have developed a resistance to sodium fluoroacetate, a toxin commonly found in many native Australian plants.
Male kangaroos have another notable characteristic related to their scent. Locally known as 'stinkers' or 'boomers,' the males emit an intensely strong odor that resembles curry.
This smell, produced by a gland located on their chest, doesn't seem to serve any obvious purpose other than deterring predators from attempting to eat the kangaroos. Even Aboriginal people will only resort to eating these kangaroos in extreme circumstances.
