BEYOND THE FIVE
10 Weird Senses Humans And Other Animals Have
Published on April 7, 2024
Image: Bacila Vlad
Who said there are only five senses? While humans rely heavily on sight, smell, taste, touch, and hearing, there are many more sensory abilities in both humans and animals, some of which can seem bizarre or even otherworldly.
From detecting magnetic fields to perceiving infrared light, here are 10 extraordinary senses that will challenge your understanding of animal perception.
Proprioception
Image: Inge Poelman
Despite having a weird name, this is by far one of the most standard senses among living organisms. Humans and animals alike rely on proprioception to perceive the position and movement of their bodies in space. This sense operates through specialized receptors (mechanosensory neurons) located in muscles and joints, providing crucial feedback to our brains for keeping balance, coordination, and doing precise movements.
Magnetoreception
Image: Jametlene Reskp
Some animals, like birds, turtles, and even some insects, possess the remarkable ability to sense Earth's magnetic field. This sense, known as magnetoreception, allows them to navigate during migration or find their way home with astonishing accuracy. In fact, some scientists argue that humans might have a latent or even subconscious ability to perceive Earth’s magnetic field through a number of receptors located in the optical retina.
Echolocation
Image: TJ Fitzsimmons
Bats and dolphins are well known for their use of echolocation, emitting high-frequency sounds and interpreting the echoes to navigate and locate prey. A form of active sonar similar to the one used by ships and submarines, this extraordinary sense enables them to "see" their surroundings even in complete darkness. Interestingly, some insects that are hunted by echolocating bats have developed active countermeasures against them, using ultrasonic clicks for echolocation jamming or by imitating the call of toxic species.
Electroreception
Image: Amos
Sharks, rays, and certain fish have electroreceptive organs called ampullae of Lorenzini, allowing them to detect the electric fields produced by other animals. In most species, this sense is paired with the ability to generate weak electric fields of their own. This unique sense aids in both navigating and hunting in murky or dark waters, where traditional senses might fall short. Monotremes like platypus and echidnas have curiously evolved a similar sense of electroreception to aid them in finding food.
Thermoception
Image: Wolfgang Hasselmann
Thermoception or thermoreception is the sense that aids in detecting changes in the surrounding temperature, and it is the reason anything feels hot or cold. In large animals, like humans, thermoception occurs mainly in the skin. But some species, like pit vipers, possess specialized organs capable of detecting infrared radiation, allowing them to sense heat from prey or predators. Recently, scientists have discovered that dogs possess thermoreceptors within their noses, allowing them to detect weak thermal changes in front of them.
Hygroreception
Image: Alexander Grey
Certain insects, such as ants and locusts, possess hygroreceptors that allow them to detect humidity levels in their environment. This sense helps them find suitable habitats, avoid desiccation, and regulate behaviors like nest-building and foraging. And while you might think humans can also tell whether something is wet or not, the truth is we don’t have any hygroreceptors, and can only infer wetness through contextual clues - as wet objects tend to be colder or feel slippery.
Pheromone Reception
Image: Mikhail Vasilyev
Many animals, including insects, mammals, and even some reptiles, communicate using pheromones – chemical signals similar to hormones that trigger social or reproductive behaviors. This sense plays a vital role in mate selection, territory marking, and coordination within social groups. Social insects make extensive use of this ability to coordinate complex colonies and establish hierarchies.
Vestibular Sense
Image: Franco Antonio Giovanella
The vestibular system, found in the inner ear of humans and most vertebrates, contributes to balance, spatial orientation, and sense of motion. This sense is made of two main components or specialized organs: semicircular canals that indicate rotation, and otoliths, which help perceive linear acceleration. This intricate sense helps us stay upright, perceive gravity, and coordinate movements, essential skills for activities like walking or running.
Chronoception
Image: Aron Visuals
While the subjective experience of time might not be associated with a specific sensory system, scientists seem to agree that there are a series of complementary mechanisms that allow humans to perceive the passing of time. In fact, some animals exhibit remarkable abilities to perceive temporal changes, a crucial ability for survival. It has even been suggested that smaller animals with a fast metabolic rate tend to experience time more slowly than larger species with slower metabolic rates.
Pressure Sensitivity
Image: Marcus Löfvenberg
Certain animals, like the African elephant, possess incredibly sensitive pressure receptors called Pacinian corpuscles in their feet, which allow them to detect minute seismic vibrations and communicate over long distances. This acute sense of touch, paired with their exceptional hearing, plays a crucial role in social bonding, navigation, and detecting potential threats in their environment.
