As you may have noticed, it can be quite difficult to find an earthworm’s head altogether. They do not possess eyes, or ears, but do have mouths (that work quite differently to our own). But what about nasal cavities – have you ever tried looking for a worm nose?
No, worms do not have noses. With that in mind, how does a worm breathe? How does it smell? How does it navigate the earth?
How Do Worms Breathe?
As worms do not have noses like we humans do, it is only natural to wonder how they breathe.
As it happens, worms do not breathe oxygen the same way we do at all.
They possess neither noses nor lungs. In fact, they breathe through their skin.
This is why it is essential for a worm’s environment to stay moist at all times; otherwise, they can easily suffocate and even die.
Do Worms Have a Sense of Smell?
As an earthworm’s body does not have a nose, how can they smell? Are they capable of smelling anything at all?
Along with the capacity to breathe through their skin, earthworms also have receptors all along their skin.
These receptors, also known as photoreceptors, work as light-detecting cells. Do you know how worms see or do they see at all or not?
These cells allow earthworms to detect where they are with regard to the light (that is to say, whether they are on the surface of the ground or deep within the soil).
Earthworms need their light receptors to ensure that they are not exposed to direct sunlight for too long.
In direct sunlight, an earthworm can survive approximately one hour before drying up and dying.
These features are incredibly sensitive and are believed to be more than just light receptors.
In fact, some believe that these receptors on the worm’s body can also sense vibrations, detect smells and even some tastes.
It is believed that thanks to the smells that they can receive, they are better able to detect where their next food source is.
The fact that they can detect vibrations is also essential to their survival.
Vibrations in the ground can be a sign of rain, thus alerting the earthworms that their environment is about to become too moist for their comfort.
It can also be a sign that predators are approaching and that they should therefore leave as quickly as possible.
How Do Worms Locate Their Food without A Nose?
As stated, it is believed that the earthworms use their senses of smell from their receptors to locate the nutrients in the ground that they need to eat to survive.
Using the small bristles on the outside of their skin, the worm will contract and release their circular muscles and their longitudinal muscles to burrow through the soil in order to reach their food.
Their receptors, muscles and nerves, are all connected to their brain, called the cerebral ganglion.
Naturally, a worm also needs its heart to help it to retrieve its food and survive.
Worms have five hearts that pump blood through their bloodstream, feeding their circulatory system as they live.
What Else Do They Use Their Receptors For?
As was previously mentioned, earthworms use their receptors to detect light, vibrations, and possibly even taste and smell.
Worms need their receptors to thrive in their surrounding environment, and without them, worms would be truly helpless!
However, it is true that “ their eyes can deceive them ”.
That is to say that, for example, when an earthworm senses vibrations in the ground, they tend to head straight from their burrows towards the soil surface in order to avoid animals in the ground like moles, which could eat them.
However, many other animals have found a way to use this to their advantage.
Birds, for example, will tap the surface of the ground with their beaks repeatedly, creating vibrations that run through.
Soon enough, earthworms will rise, having been tricked by the clever birds, only to be taken away and eaten.
In conclusion, worms live without noses, eyes, and even ears!
However, do not worry about our friend the earthworm, as they do manage very well with the features that they do have.
Thanks to their efficient receptors, their strong bristles, and their sensitive skin, earthworms are easily able to breathe, move their body forward, and roam the world as they please.
Earthworms reproduce at a very quick and efficient pace, too!
Thanks to a lot of mucus, earthworm cocoons, and their fascinating reproductive organs, two worms can reproduce for their species a few times a month!
If you are interested in learning more about how earthworms reproduce, check out our article “ Do worms have genders? ”