Most organisms that can “see”, or create an image their surroundings, use either photoreception (sight) or mechanoreception (sound, in the form of echolocation).

I am considering a fantasy race that instead uses chemoreception (taste or, more probably, smell) to build up an image of their surroundings. My gut (ha ha) tells me this is unlikely, as scent molecules follow a more meandering path than either photons or sound waves, so it seems unlikely a creature could form an image of their world based solely on this.

However, I thought I might as well post the question to see what others think.

No magic allowed.

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    $\begingroup$ I'd say your gut is correct. Not only do the molecules follow a more meandering path, but they do so very slowly when compared to sight and sound. A given molecule of any volatile takes hours on average to cross a room. So your perception range would be short and delayed, and there are many materials that are non-volatile, and have effectively no emitted molecules that could be used to detect their presence. $\endgroup$
    – jdunlop
    Commented Jun 11 at 0:36
  • $\begingroup$ Maybe if a sensor array is spread across wide distances. $\endgroup$ Commented Jun 11 at 1:33
  • $\begingroup$ I can imagine that a space-whale would be able to smell a distant (sunward) planet as the atmosphere is slowly carried away by the solar wind.... $\endgroup$
    – sdfgeoff
    Commented Jun 11 at 10:59
  • $\begingroup$ Yes! I don't have time to write a full answer or a copy of the reference handy... Recommended reading: An Immense World: How Animal Senses Reveal the Hidden Realms Around Us by Ed Yong. $\endgroup$
    – Theodore
    Commented Jun 11 at 20:03

2 Answers 2


We smell in stereo.

In an experiment, people were asked to follow a short trail of chocolate scent across grass. Those who could do it developed a technique of moving their head from side to side to use alternate nostrils. This let them compare two regions, and to correct for the adaption that masks out constant scents. Tracking dogs can do the same when they lose a scent and want to pick it up again.

This is not a camera-like imaging, which I think is what you had it mind. It is more like feeling your way across a surface.


The Goodest Bois - the Blood-hound


Firstly - look at that Snoot, observe that it is Boopable and the adorable Ear-flaps

Okay, now for a more serious answer - when you say 'See' it's world around them, whilst it might not have the resolution of say Sonar (or equivalent echo-location in certain mammals) - I don't see a reason why a very directional and sensitive means of smelling could not be used to navigate, it would have it's downsides like all other means of forming an Image (if it is foggy or too bright or too dark for vision, or noisy/hard reflective surfaces for Echo-location)

And to be honest - the idea of a race of sentient bloodhound people is awesome - and so my answer is:

Yes, it would be possible

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    $\begingroup$ A wonderful snoot indeed. $\endgroup$
    – user98816
    Commented Jun 11 at 10:32
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    $\begingroup$ Tracking and navigating seem like they might be possible, but that's not what the OP was asking for. Even a dog's wonderful snoot can't let them know if a rock is tumbling down a hill towards them. Scents alone don't make sense. (Also, nitpick, sapient bloodhounds. Doggos are already sentient.) $\endgroup$
    – jdunlop
    Commented Jun 11 at 18:53
  • $\begingroup$ @jdunlop - I mean, sure Smell would have issues - but plenty of people who can see and hear have been hit by falling Rocks - so I kinda think you can make an argument that it is not a critical disadvantage $\endgroup$ Commented Jun 11 at 21:30
  • $\begingroup$ "Plenty of people who have vision have crashed their cars, so obviously blind people should be driving too." That other vision systems can fail at a task doesn't mean it's reasonable to substitute with a system that always fails at a task. $\endgroup$
    – jdunlop
    Commented Jun 11 at 21:33
  • $\begingroup$ @jdunlop - there are days where I wonder if blind people are driving... I see what you mean, however I think that if we accept some limitations of smell (long distance avoidance), you can still functionally navigate. $\endgroup$ Commented Jun 11 at 21:39

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