Hello, I'm a neuroscientist with a focus on comparative cognition and animal behavior. I've spent a considerable amount of time studying the nervous systems of various creatures, including invertebrates like worms.

Worms, particularly the common earthworm, have a nervous system that is quite different from our own. They lack a brain and a centralized nervous system, but they do possess a series of nerve cords that run the length of their bodies, which allow them to respond to stimuli.

The question of whether worms experience pain is complex and hinges on the definition of pain. Pain in humans is generally associated with a conscious awareness of discomfort, which is linked to our emotional and cognitive processing capabilities. Since worms do not have a brain or the same level of cognitive function as humans, it's unlikely that they experience pain in the way that we understand it.

However, worms can react to harmful stimuli, such as touch, heat, or chemical irritants, which might cause them to move away from the source of discomfort. This is an instinctive response rather than a conscious experience of pain.

In summary, while worms have the ability to detect and respond to harmful stimuli, it is not clear that they have the necessary cognitive structures to experience pain as complex animals like mammals do.

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But animals with simple nervous systems, like lobsters, snails and worms, do not have the ability to process emotional information and therefore do not experience suffering, say most researchers. ... But vertebrates with spines have much more advanced nervous systems and can feel real pain and suffering, Stevens explained.read more >>