We are so used to our own concept of what our nose looks like that we try to assume every creature on the planet has one. If you’ve got a pet spider, you may well have wondered if they have a nose or not?
Spiders do not have a nose. Their faces mainly comprise of eyes and a mouth. They do have a sense of smell, which they achieve through an intricate network of hairs on their legs.
That’s the simple answer – they are one of nature’s animals without a nose.
But then, that opens up a wide range of other questions that are worth exploring. After all, what are those holes you see on their head? How do they get air into their bodies in order to breathe?
Well, read on to learn everything you need to know about spiders and their lack of having a nose.
Breathing and Smelling Options are Different
We use our nose in order to smell things as well as to breathe, but a spider goes about both of these things in completely different ways. So, we should explore both of these areas to get a better understanding of how on earth your pet spider is able to survive without a nose.
First, let’s look at the breathing part.
How a Spider Breathes
Even though there are some subtle differences between species, all spiders will pretty much breathe in the same way. A spider has something known as ‘book lungs’ and you need to go to their abdomen in order to find them. Also, they have their own trachea, so yes, they do have a windpipe, but it’s still not connected to any sense of them having a nose. [Source]
With these book lungs, they consist of layers of thin, hollow plates that resemble fine pages on a book, and that’s how it got its name. These pages are open to the air thanks to small slits on the abdomen of the spider. However, a few species will have these pages on their legs, but they still work in the same manner, and get air into the body of the spider.
These pages will expand and contract, like our own lungs do, in order to pull oxygen into the body. All of this is achieved without the need for a nose.
The way in which a spider can breathe is pretty cool. These slits in their abdomen not only allow air to come in, but they also let the used air back out. This is clearly the same type of thing we do when breathing through our nose, but it’s more a case of the air getting straight into the actual lungs rather than what happens to us humans.
One interesting side note. Modern spiders have only one set of book lungs. In primitive spiders, they have two sets. However, the modern spider has evolved, so one of the pairs has now turned into tracheae to help the oxygen to get around their body. This alone is a perfect example of how evolution can work and change aspects of creatures that are very familiar to us.
So, your spider breathes without the need for a nose, but what about the other way in which we use our nose? The issue of smelling.
How a Spider Smells
We also use our nose in order to identify smells, so if a spider doesn’t have a nose, then how do they manage to pick out smells? The answer is more intricate and cooler than you would expect.
Well, a spider is able to detect a scent through a network of highly sensitive hairs that cover their legs. They have evolved to such an extent that they can identify if the smell they are picking up is beneficial to them, which means something is edible, or if they should get away as danger is present.
A spider actually has an amazing sense of smell. They use it to hunt out mates, as well as detecting prey. Keep in mind that their vision is relatively poor, so nature has helped make up for that by heightening other senses, and smell is one of the primary ones for your spider.
Also, be aware that some species smell more through two tiny legs that are near their mouth. These small legs are known as pedipalps. They also use them to hold onto their prey as they inject poison into them, so they are useful things for them to have.
The cool thing is that it does mean your pet spider has various ways of being able to smell items. There’s even some debate as to whether they can differentiate between flavors, and not just something that smells to them.
Whenever these hairs are triggered by something, it will immediately send signals to their brain. They can then process what is going on, and this is clearly similar to what our brain does when we catch a whiff of something with our noses.
More About Their Breathing and Sense of Smell
So, we have established that your pet spider does not have a nose, but we get it that you want to know more about how they perform the functions that we use our noses for.
Remember how we said they had a series of thin pages, like a book that would expand and contract? Well, they are connected to an intricate network of hollow tubes. Those tubes form part of the network that takes oxygen and fires it around their body to allow them to breathe.
The tubes work in the same way as the tubes that are in our own lungs. It’s just the way in which the oxygen gets into there that’s different with a spider.
Also, we need to mention something else that’s important about those hairs on the legs connected to the sense of smell.
With the hairs on their legs, they do something amazing. They break down the chemical composition of a scent, which the spider can then study and determine if it’s friend, for, or food. It does this in an instant, and it’s actually impressive how quickly they can decipher what is going on through their sense of smell. [Source]
Your pet spider is going to smell things, not via a nose, but by touching things with their legs. The amazing thing is that their legs and sense of smell is so delicate that they can differentiate if something caught in their web is edible or not just by touch. That’s why you sometimes see a capture in a web, and the spider isn’t interested. It’s because they know they cannot eat it, so they leave it alone.
Also, some species can have over 100,000 of these hairs on their limbs, and that’s why their sense of smell can be so acute. If you pick up your pet tarantula and allow them to walk on your hand, then they will actually be smelling you at the same time, and that’s sort of cool.
But They Don’t Like Every Smell
Your spider has an amazing sense of smell, but it does mean it’s all too easy for it to pick up certain scents that are less than appealing to them. In fact, some scents can repel a spider, so if you are a new spider owner, then it’s best to understand the aromas that will make them run.
Scents such as vinegar, citrus smells, and peppermint oil repulse them. With most of those scents, it’s the sharpness of the smell that they hate. We aren’t saying that any of those scents will make them ill or hurt them, that’s not the case. However, it will certainly upset their senses, and that’s not something you want to do to your pet spider.
But you must remember one important point.
An airborne smell is going to do nothing to a spider. They won’t pick up on it, no matter how pungent an aroma it may be. However, put that smell on a surface that they can come into contact with, and if they don’t like it, then they will turn away from the scent.
No Nose Doesn’t Mean Any Additional Problems
For us, it’s strange to think about what life would be like without a nose. The problems we would face would be impossible to deal with, but it’s not a problem for a spider.
The spider has managed to evolve over millions of years to such an extent that their ability to smell is so fine-tuned that it works way better than our own noses. They need this because it’s such an integral part of their survival. Your pet spider may never have to worry about various things, but those instincts are going to appear in them naturally.
They don’t need a nose. They have other methods of doing all of the actions that we use our noses for, and they are substantially better at it in some ways.
Spiders Can Sense The Smallest of Things
One of the coolest things about spiders has to be that their senses, which includes their sense of smell, are so acute that they can pick up on the smallest amount of scent far beyond what we can detect as humans.
Of course, some could argue it’s all relative to their size, but that’s not true. Their ability to pick up on even the smallest of things is amazing. From microscopic insects that could be food to simply sensing anything that’s around them. This is all done through feeling it, and it’s an impressive feat of nature.
So, What’s On Their Face Where We Have Our Nose?
If your spider doesn’t have a nose, then what do we see on their face where you may be looking for a nose?
Well, all you see are their eyes, and their jaws, which also contain their fangs as well as their mouth. Remember, your pet spider doesn’t have ears either, so they are also missing from this picture. They are all on a part of the spider called the cephalothorax, and this is one of the few parts that make up the body of the spider.
It’s also the place where their brain is contained.
The mistake people often make is looking at those eyes and then linking a couple of them to something that would be like our nostrils. This is wrong. It’s a case of us trying to give a spider some attributes that are more familiar, and the idea of anything existing without a nose just feels wrong.
Your Spider Simply Doesn’t Need a Nose
Basically, what we are saying here is that your spider does not even need a nose. They have their own way of doing things, and no nose is required.
Your spider breathes via an efficient system. They pick up on scents and smells through a finely-tuned system. They have managed to do this thanks to their need for survival. They have never had noses, and some are almost completely blind, so turn to other senses that are more alert and alive compared to what we could experience.
Your pet spider is very efficient at what it needs to do in order to stay alive. Not having a nose is certainly not the end of the world.