Touchy Feely

Touchy Feely, photo courtesy of Kirsten Cowling

Humans don’t like being in the dark.  We have our favourite sense – vision – and then we have a range of second class citizens that we think of as useful in helping us make sense of what we see.  About 30% of our brain is devoted to receiving, processing and interpreting information we receive through our eyes.  For example, there are 5 times as many cells in our visual cortex as there are in our auditory cortex.

Because we’re so biased towards using vision, we tend to avoid situations where our vision isn’t great (although as I get older, I notice that I’ve become a bit less demanding in this area and seem to operate happily with things near the horizon forming an attractive airbrushed blur!).

As a species, we prefer daylight, although we’re happy enough at night provided there’s plenty of artificial light. Once daylight disappears, we find that things lose their colour, and we’re less good at working out how far away things are.  There’s nothing worse than a poorly lit restaurant… humans get a bit twitchy when we can’t quite see what we’re eating.  That’s despite the fact that we have perfectly functional senses of smell and taste!

A few weeks ago, on one of my regular cinema trips, I saw the film “About Time”, where there’s a funny scene in a restaurant with no lights.  People try to work out what they’re eating.  And even where the food is… Things are dropped.  Food is missed. Food ends up in people’s hair and on their faces…

Because we’re so anthropocentric, we believe that all animals have the same strengths and weaknesses that we do, and it rarely occurs to us that other species may have abilities we don’t.  We are willing to acknowledge that we can’t really imagine what it would be like to be a bat, able to navigate perfectly in the dark using sensory information we just don’t have. We are amazed to hear that some animals are able to use electric fields to “see”, or that bees are able to work out which flower has recently been visited by another bee based on it’s electric charge. Despite this, we make our pets and domesticated animals into small or large furry versions of ourselves.  Horses are no exception, and many people feel happier knowing their horses are inside at night. After all, if they were outside, how on earth would they get around?  They might fall over something in the dark! Or blunder into a tree, or fall into a pond!

Well, I’m here to tell you that your horse has a sense you don’t have. They’re just as exceptional and amazing as a bat, or a bee, or a pigeon who can navigate using information from the earth’s magnetic field.  Take a look at your horse’s face, and you’ll notice there are long whiskers sticking out above their eyes and around their muzzles.  We call them whiskers, but we’d actually be more correct to call them “feelers”, because that’s what they are.  Here’s an experiment to try.  Get a friendly person to pick a single hair from the centre of your scalp (it helps if you have quite long hair!).  Close your eyes, and ask them to move the hair like a joystick, left, right, forward and back.  If they’re not pulling on the hair, you won’t be able to feel that it’s being moved. You won’t be able to tell whether it’s moving left or right, up or down.  There are no special cells in your brain devoted to receiving and processing information about the movement of your hairs.  That’s where you and your horse are different.  A horse’s brain contains a set of cells that receive information from their whiskers.

This information is divided in two – and in this way, it’s a bit like the information we receive from our fingertips.  If you close your eyes, and someone touches your fingertips, you know when it happens: our skin is a passive receiver of information about what the world is doing to us.  At the same time, we actively gather information using our fingertips, to find out about the shape and texture of things around us.  We are able to construct 3D images in our brain using information gathered this way: with your eyes closed, you can still easily tell the difference between a ball and a cube, just using your fingertips.

Horses don’t have fingertips, but they do have whiskers.  Whiskers are passive receivers of information, like our fingertips: a horse can tell the direction of a breeze, based on the tiny pressure on their whiskers.  They receive communications from other horses in the herd – horses will sometimes look at one another and touch whiskers without any skin to skin contact.  If you’ve ever had a butterfly kiss from a horse, you’ll know what I mean by this.  They are also able to use their whiskers actively.  In winter, my horse who lives outside spends more hours in the dark than he does in the daylight.  He needs to be able to navigate, he needs to be able to work out distances, he needs to know what he’s eating.  I don’t think anybody’s done the experiment with a horse that’s been done with rats, but I’m pretty sure you would have no trouble training a horse to recognise the difference between a ball and a cube using whiskers alone.

A horse’s brain is able to tell exactly what direction a single whisker has moved when in contact with an object, and given that they have a whole muzzle full of them, you can see how touching a ball and touching a cube will move different whiskers in different directions.  Horses also have a blind spot just under their muzzles – so no surprise that if they want to know what’s down there, they use their whiskers to find out.  Many horse owners (and I include myself in this count) have watched their horses test whether there’s a current running through an electric fence by bringing their whiskers almost within touching distance of it.  When my horse decides it’s actually not on, and then happily leaps the fence into the luscious long grass, I’m never too sure whether I should be full of admiration or horrified.  Admiration has always won out so far!

Whiskers are also more versatile than fingertips: they are not damaged by coming in contact with things that hurt.  If we grope around in the long grass at night, we’re likely to end up with nettle stings.  If a horse wants to avoid nettles and brambles in the dark, they can use a combination of whiskers and their sense of smell to work out what’s under their nose and how close it is.

Unlike our fingers, whiskers themselves are just hairs: they don’t have any pain receptors.  This is most likely because a horse will wear down whiskers, and occasionally shed them, just like other hairs.  So if you cut your horse’s whiskers, they won’t yelp or run off, it hurts them no more than we’re hurt by putting on thick gloves or a blindfold.  Mind you, those gloves and that blindfold will need to stay on for months, because that’s how long whiskers take to grow back.  We don’t willingly deprive ourselves of senses, and we feel very uncomfortable when one of our senses is out of action…  we blunder around in the dark, we grope clumsily while wearing thick gloves, our food is suspect when our noses are blocked with a cold.  Why, then, are we so blasé about removing one of our horses’s senses?  We tend to justify whisker trimming because “it makes the horse look so much tidier”, and “they’re quite happy, they don’t object to being trimmed”. The horse doesn’t notice the lack of a sense until they come to use it… later that night, in the dark, while trying to pick out the weeds from the grass, or while attempting to “speak” to a herd mate and rudely bumping noses by accident.

Just because we can’t see a glaring difference in how the horse acts, we assume what we’ve done has no effect: you probably won’t notice that I’m wearing ear plugs until you repeat your question to me for the third time!  This blog post is a plea: don’t be afraid to be touchy feely. Allow your horse to be touchy feely to the utmost of her or his abilty too: leave those feelers alone!