You might be surprised to learn that humans are not the only living things on our planet to use electricity in their daily lives.
You’ve probably heard of electric eels, but if you thought they were just characters in a kid’s cartoon with zigzag lightning bolts fizzing out of them, you would be wrong. They actually do exist and there many more marine and land-based organisms that also either generate electric shocks or use electrical fields to hunt their prey, or communicate with others of their species.
Shocking news? Well, have a look at this selection of 10 super-charged animals.
10 electric animals
Electric eels
Rightly the most famous of the ‘electric’ animals, these large South American eels were instrumental in the advancement of man’s understanding of the power and uses of electricity. The eels live in the muddy bottoms of river and can tolerate low oxygen levels because they go to the surface to breath air.
They can reach 2m (6ft 7in) in length and weigh 20kg (44lb). They have an internal organ composed of long stacks of cells, like rolls of coins, that are specifically designed to generate electricity. They use this to electrocute their prey with discharges up to 600 volts. Alessandro Volta, who gave his name to the volt unit of electricity, was an Italian chemist and pioneer of electric power in 1799. He invented the first electric battery, basing his design on the anatomy of the electric eel’s organ.
Echidnas
This Australian mammal is like a hedgehog on steroids and its whiskery snout is almost unique in the mammal world. Its mucus glands contain receptors that allow the animal to detect electrical fields generated by the muscle movements of their prey.
This action is called passive electrolocation which the echidna uses at night when its sight alone would not be sufficient to detect a meal. How many of these receptors each member of the echidna family has depends on what species they are.
Long-beaked echidnas have 2,000 receptors to help them find earthworms in the wet leaf litter of tropical forests. Short-beaked echidnas only have about 400 receptors, but they feed on ants and termites so presumably a termite mound is a lot easier to find than a solitary worm.
Electric catfish
They are not as long in the body as electric eels but these chunky fish weigh about the same and deliver an electric shock to stun their dinner that is almost as formidable. The shock can measure up to 400 volts and, like electric eels, they also use their superpower as a defence mechanism.
These catfish were well known to ancient Egyptians who employed the shocks they delivered to treat arthritis. They only selected small fish, though, because the zap from a larger one, although unlikely to kill you, will certainly give you a nasty jolt.
Oriental hornets
Yet another, different use of electricity by an animal. This time it is believed, for less lethal purposes - to help it keep warm and active. This hornet’s particular exoskeleton tissues absorb sunlight and, when the light comes into contact with its yellow pigment cells,electricity is magically generated. Scientists are still not entirely sure of all the uses the insect has for its solar cells but they think they provide a lot of energy to the body, as the hornets are most active in strong sunlight. Presumably, if the oriental hornet wants to defend itself, its sting is more than enough to see off even a very large predator in short order.
Sharks
Sharks and many of the ray family have sensory organs in the shape of lateral lines that run along their bodies and over their heads and help them detect electrical fields in the water around them. These lines contain small jelly-filled electroreceptors that have been given the name ampullae of Lorenzini, after the 17th century zoologist who first described them.
All living things generate a small amount of electricity as they move around, and sharks are super-sensitive to those faint traces. So ‘feeling’ electrical fields helps them find their prey and avoid competitors. The degree of electricity also tells them the size of the animal they are approaching.
Electric rays
These are different to most rays in that they don’t confine themselves to detecting electrical fields to find prey, they deliver a stunning shock of up to 200 volts to kill it. The fish’s Latin name torpere comes from the word for ‘stiffened’ or ‘paralysed’, which is the effect you get when you touch the animal – in the case of small fish, that’s immediately before you get swallowed whole.
From that torpere name we get the term given to an underwater missile, the torpedo, similar in its deadliness. In ancient Greek medicine electric rays were used to numb the pain of childbirth and operations and the Romans treated headaches and gout with them.
Duck-billed platypus
The cutely familiar aquatic mammal has a couple of less than cute tricks up its sleeve when to comes to finding food and defending itself. It can deliver a highly venomous jab from a spur on its hind foot. And, like the echidna, so far as using electricity is concerned it has specialist glands that lie on the underside of its bill in stripes.
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These are more extensive than are found in any other passive electrolocation animal and sensitive enough to pick up even tiny electric currents generated by the muscles of its worm or shrimp prey. The platypus sweeps its head from side to side as it hunts and the signals it detects are thought to help it judge distance to the prey as well as its exact location.
We named the Duck-billed platypus one of the weirdest animals in the world
Stargazers
There is a whole family of stargazer fish (one of the world's weirdest fish), of which two – astroscopus and uranoscopus – are known to pack an electric punch. Dr William Leo Smith, Head of Fishes at the Department of Zoology in the Field Museum in Chicago, has called these stargazers “the meanest things in creation” because they ambush their prey and deliver both an electric shock and a hefty dose of venom.
Astroscopus have their shock-delivering organ within modified eye muscles, while uranoscopus have theirs in their sonic muscles. They look pretty gruesome, too, with their bulbous eyes on the top of their heads and two curved rows of savage jagged teeth.
Honeybees
As they buzz through the air seeking out pollen, honeybees’ wings generate a positive charge of static electricity. Flowers are naturally negatively charged and the combination of the two ensures the pollen sticks to the bees to be transported back to the hive.
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Not only that, but scientists also believe that each bee leaves an electrical charge ’message’ on the flowers they visit, that another bee can detect. This avoids the second bee wasting its time visiting a flower that has already been stripped of its pollen.
Studies have also been done on the effects of agrichemicals on the electrical signals given off by blossoms. It’s thought that these can be altered by the chemicals so that the flowers become less obvious to the bees.
Knifefishes
These fish have specialist electricity generating organs to help them find prey. Unlike the fishsuch as sharks that are sensitive to the electrical impulses created by other animals, knifefish make their own weak electric waves that they send out from their muscles. This is called active, rather than passive, electrolocation. The waves hit an object and bounce back, which helps the knifefish navigate around its territory and seek out its favourite food in a similar way to the way an echolocating animal uses sound waves. The electric signals are also thought to be used as a form of communication between fish of the same species – telegraphing their intentions, as it were.
