Animals Wildlife 11 Animals That Have a Sixth Sense By Bryan Nelson Writer SUNY Oswego University of Houston Bryan Nelson is a science writer and award-winning documentary filmmaker with over a decade of experience covering technology, astronomy, medicine, and more. our editorial process Twitter Twitter Bryan Nelson Updated May 31, 2017 Photo: Lars Christensen/Shutterstock Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species The famous philosopher Aristotle was the first to assign humans with five traditional senses: sight, hearing, touch, taste and smell. However, if he was categorizing animals, his list of senses might have been longer. Several animals possess additional perceptive abilities that allow them to experience the world in ways we can barely imagine. Here's our list of 11 animals that have a sixth sense. 1 of 11 Spiders Photo: USGS Bee Inventory and Monitoring Lab/flickr All spiders have unique mechanoreceptory organs called slit sensilla, which allow them to sense minute mechanical strains on their exoskeleton. This sixth sense makes it easy for spiders to judge things like the size, weight, and possibly even the type of creature that gets caught in their webs. It may also help them tell the difference between the movement of an insect and the movement of the wind, or even a benign blade of grass, as it moves across the web. 2 of 11 Comb jellies Photo: evantravels/Shutterstock These majestic gelatinous creatures have specialized balance receptors called statocysts that allow them to orient themselves among the ocean's currents. Since they don't have a centralized nervous system, comb jellies also rely on this specialized sense to better coordinate the movements of their cilia to reel in food. 3 of 11 Pit vipers Photo: Care_SMC/flickr Venomous snakes of this family of are most easily identified by a pair of deep "pits" that can be found between the nostril and the eye. These pits are actually heat-sensing organs that allow the snakes to see in infrared — an invaluable sixth sense for a predator that often hunts at night. The sense is so sensitive that pit vipers can accurately judge the distance and size of their prey even when their other senses are deprived. 4 of 11 Pigeons Photo: bluelake/Shutterstock Many migratory birds have an amazing ability to detect Earth's magnetic field, a sense they utilize like a compass to navigate great distances. This sense is called magnetoreception, and few birds perform it better than pigeons, especially domestic homing pigeons. Pigeons have iron-containing structures in their beaks, which are arranged in a complex three-dimensional pattern. This gives the birds an acute sense of spatial orientation, allowing them to identify their geographical position. 5 of 11 Dolphins and porpoises Photo: Willyam Bradberry/Shutterstock These charismatic sea mammals have the incredible sixth sense of echolocation. Because sound travels better in water than in air, dolphins are able to create a three-dimensional visual representation of their surroundings based entirely on sound waves, much like a sonar device. This is a necessary adaptation, especially for river dolphins, because vision is often extremely limited in murky water. Dolphins can navigate through a river of tangled branches with ease even if their eyes completely covered. 6 of 11 Sharks Photo: nicolas.voisin44/Shutterstock Electroreception is the amazing ability of sharks and rays to detect electrical fields in their surroundings. In fact, the strange shape of a hammerhead shark's head is specially designed for an enhanced electroreceptive sense. Because salt water is such a good conductor of electricity, sharks with a refined sixth sense can detect their prey from the electrical charges that are emitted when a fish contracts its muscles. The sense is so sensitive that some sharks can pick up the change in electrical current of two AA batteries that were connected 1,000 miles apart, even if one was drained out. 7 of 11 Salmon Photo: Bill Perry/Shutterstock These fish somehow find their way back to spawn in the same rivers from which they were born, despite traveling great distances in the open ocean during their adult life. How do they do it? Though it is still largely a mystery to science, many suspect that salmon utilize ferromagnetic mineral magnetite deposits in their brains to pick up the Earth's magnetic field. It has also been discovered that they have a refined sense of smell and can tell the difference between the smell of their home stream from any other. 8 of 11 Bats Photo: U.S. Fish and Wildlife Service Northeast Region/flickr Many insectivorous bats, often referred to as "microbats", are capable of using echolocation to catch their prey and for navigating through dark caves and the night sky. They have a larynx capable of generating ultrasound, which they emit through their mouths or nose. As the sound echoes through their surroundings, sound waves bounce back and give the bats a radar-like "view" of their surroundings. In fact, these bats often have strange, wrinkled faces that function like an ear to better pick up the sound. 9 of 11 Weatherfish Photo: Geza Farkas/Shutterstock Weatherfish, or weather loaches, have an incredible ability to detect changes in pressure. They use this sense to monitor buoyancy underwater and to compensate for the lack of a swim bladder. Remarkably, this sixth sense also allows these fish to "predict" the weather, and fisherman and aquarium owners have long recognized changes in their activity as large storms approach. 10 of 11 Platypus Photo: worldswildlifewonders/Shutterstock These bizarre, duck-billed, egg-laying mammals have an incredible sense of electroreception that is similar to the sixth sense of sharks. They use electroreceptors within the skin of their bills to detect the electrical field that gets generated when their prey contracts its muscles. A platypus swings its head from side to side while swimming as a way to enhance this sense. The bill is also lined with mechanoreceptors, which give the animal an acute sense of touch and make the platypus' bill its primary sense organ. 11 of 11 Sea turtles Photo: idreamphoto/Shutterstock Much like salmon returning to their home stream, sea turtles also prefer to return to nest on the same beach where they were born. Given the vast distances they travel, their ability to locate their home beach is remarkable. As with many migratory animals, sea turtles accomplish this feat by measuring the Earth's magnetic field. However, their ability cannot account for deflection from ocean currents, and some turtles wander aimlessly for long periods of time at sea when currents are strong. Maybe this handicap explains why they live such long lives!