The anatomical structure of worms
The best-known worms are earthworms, so that we will refer to them. However, there are other types of worms with similar anatomical structures.
Earthworms spend their lives creating burrows in the soil or rotting organic matter. In the process of evolution, the worm body was adapted to this type of life, and any sign of an external organ (e.g., limbs) that might interfere disappeared without a trace. Earthworms do not have eyes or any other sensory organs in the front of the body and outside it. The worm’s body is built in the shape of a cylinder when it is thick in the middle of it and becomes narrower on both sides. This structure allows worms to dig more easily. The front of a worm is easy to spot – all you have to do is watch its movements—a kind of swollen ring (clitellum) in its anterior part, extending along several sections. The worm’s body is divided into many sections marked as rings along its entire length. These rings are attached to each other and surround the worm’s body. The mouth is near the first section. Above the mouth, there is a small flap called the prostomium. Worms have a nervous system but not really a brain.
So – Do worms sleep?
When we talk about sleep, we refer to the phenomena that occur in our brain while we call it “sleep” and the closing of eyes that happens during sleep.
How can a creature that has no brain and no eyes sleep?
So, If you mean ‘sleep,’ as in humans in which the brain waves move to a different rhythm and the eyes are closed, worms do not sleep. Although worms do have cycles of inactivity that you may want to define as “sleep.”