Yesterday I was driving at night on an unlit road (nothing nefarious, I swear), and there was a truck behind me with a ridiculous amount of headlamps on, and catching a glimpse of it in my mirror it looked a bit like an angry animal. It got me to thinking, if there was an animal that could switch on headlights in the jungle, it could scare off quite a lot of predators.

Now I know that there are fish, like the electric eel (whose scientific name is "Electrophorus Electricus", which I find rather hilarious) that can use electricity for hunting and communication and self-defence. But I'm wondering if an entire species (like all types of cats for example) could have evolved to use electricity for similar purposes.

And I'm not talking properly Pikachu style, just channel enough electrons to create a bright light source for a limited amount of time, to scare off predators or to startle prey for example.

I don't know if this would be through bio-luminescence, like an angler fish, or more like an actual light bulb, by running electrons through some sort of natural filament to create the light. Whichever one is possible to create a significant amount of light really.

This animal doesn't necessarily have to have evolved on the Earth we live in now, it could have any conditions to evolve.

So my main points of the question are:

  1. Could an animal evolve to use electricity which could power, let's say as an example, two 85 watt bulbs for 5-10 seconds?

  2. Could an animal use this electricity to produce things like light for their survival and that of their family, be it through hunting or protection?

  3. Bonus: If such an animal/species were to exist in a habitat on land (like in the mighty jungle), would other animals that currently exist on our planet be able to coexist with this animal, as its predator or its prey? Or would they need to evolve to be able to catch/escape it?

  • $\begingroup$ Evolution does not work like that. It is not that an entire specie changes to another one. To begin with, an australopithecus will always be an australopithecus, their offspring might be something somewhat different (but then again, not too different). A cat won't evolve into an electric cat, but may be an antecesor of the electric cat. And, for a long time, there will be both "evolving" and "unchanged" (or following other evolutionary paths) individuals, until the changes are too big for all the descendants to be considered members of the same species. $\endgroup$
    – SJuan76
    Apr 21, 2015 at 10:21
  • $\begingroup$ @SJuan76 I know evolution doesn't work like that, I'm saying could an animal, for example the common ancestor of the cat, evolve to be able to use electricity, and then evolve further to have different sub-species like a cat does (like lions and jaguars and all the types of domesticated cat) but all with the ability to create a natural bright light source. $\endgroup$ Apr 21, 2015 at 10:31
  • $\begingroup$ Electric eel $\endgroup$
    – user6760
    Apr 21, 2015 at 10:44
  • 1
    $\begingroup$ Check out this link $\endgroup$
    – Abhishek
    Apr 21, 2015 at 11:23
  • 1
    $\begingroup$ I think you're making an assumption here - why would natural headlights scare away animals? If it's a prey defense, eventually a predator will adapt and realize lights = dinner. $\endgroup$ Oct 28, 2015 at 21:37

2 Answers 2


This doesn't sound too unreasonable except that organisms rarely use electricity to create light. Metal filaments are in short supply in nature.

1: Yes but you'd need a decent explanation. Perhaps a large decedent of something like an electric eel which evolved to prey on very large prey and needs to provide a large jolt. Though they're unlikely to produce a 5-10 second pulse since a shorter more powerful pulse is more likely to be useful as a weapon.

2: It tends to be vastly more efficient to make light with chemicals.Doing so with electricity wastes a lot of energy.


Some species glow as a warning that they're poisonous; others confuse or blind attackers by releasing clouds or jets of light-emitting chemicals while trying to escape.

Some marine organisms, if attacked, produce what scientists call a burglar alarm - a visual 911 call designed to attract a larger fish that's only too happy to gobble up the flashy prey's assailant.

3:I don't see why not though out of water such an animal would probably need direct physical contact. If it was a major predator you can be sure other species would evolve many methods for counteracting electrical shocks.

  • $\begingroup$ Only technically primitive humans use electrically-heated filaments to create light. The rest of us have moved on to CFLs, LEDs, and similar. I don't offhand see any reason why life couldn't evolve an organic LED, or use electroluminescence: en.wikipedia.org/wiki/Electroluminescence $\endgroup$
    – jamesqf
    Apr 21, 2015 at 19:03

Electric Eel produces enough electricity to light a LED bulb for half a second. Traditional filament bulb - not really.

In the electric eel, some 5,000 to 6,000 stacked electroplaques are capable of producing a shock at up to 600 volts and 1 ampere of current (600 watts) for a duration of two milliseconds.

I'm not sure if it would manage 160 watt for 10-15 seconds, but it's well enough to seriously shock any animal (including humans) that threaten the eel.

Light bulbs are terribly lossy; they have light efficiency of order of 0.5%. Chemical-electric luminescence is far more efficient and quite a few species of the deep can "power" their glowing cells through neuroelectric impulses.

  • $\begingroup$ 600 watts for 2 milliseconds is 1.2 joules. If you stretched that over 15 seconds you'd get 0.08 watts. $\endgroup$
    – Samuel
    Apr 21, 2015 at 15:56
  • $\begingroup$ @Samuel Back when I had an electronics play-kit, I could light up a LED by hooking it up to a 9V battery with a 470 Ohm series resistor. (Please don't ask me how I remember. :)) $I=E/R$ or current equals voltage divided by resistance, for a current of 0.019 A or 0.17 W of power at 9VDC. This was some years ago already, and the LEDs that came with that kit probably weren't the lowest-power ones either. I suppose it all depends on what exactly you mean by "LED bulb", but 0.08 W is definitely enough to light up a couple of LEDs. $\endgroup$
    – user
    Apr 21, 2015 at 18:01
  • $\begingroup$ 2.4W over 0.5s; I have 3-watt LED bulbs (meant to be used in standard home lamps, brightness equivalent of a 25W filament bulb); I guess they would run too at 80% nominal voltage. The eel would need to exert itself quite a bit to produce 2 pulses per second for 15s, but tired and aching, it would still probably succeed. $\endgroup$
    – SF.
    Apr 22, 2015 at 0:21
  • $\begingroup$ @MichaelKjörling Yeah, Ohm's law, I think I read about that at some point back in college ;) I wasn't mentioning "LED bulbs", I was commenting on the statement "I'm not sure if it would manage 160 watt for 10-15 seconds". $\endgroup$
    – Samuel
    Apr 22, 2015 at 4:26
  • $\begingroup$ @SF. LEDs are current driven, but you'd just want to PWM them if you had limited energy, not drive them with lower voltage. Also, two 500 ms pulses per second is continuous power and the limited energy, the 1.2 J, would be gone very quickly. It would not succeed. $\endgroup$
    – Samuel
    Apr 22, 2015 at 4:27

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