Pain in invertebrates

Invertebrates are animals without backbones, like insects, snails, and octopuses. Even though they don't have backbones, they can still feel pain. When something hurts an invertebrate, like if it gets stepped on, a pain signal is sent from the body part that was hurt, to the brain. The brain then makes the animal feel an uncomfortable sensation, so it can try to move away from the thing that is hurting it.