Do arthropods respond to noxious stimuli purely by reflex?

Mikhalevich & Powell (2020) argue that it is wrong to dismiss the idea of sentience in invertebrates. Here, I expand on the evidence for crustaceans responding to noxious stimuli in ways that are not explained by mere reflexes, and that are consistent with pain. I consider the idea that male praying mantids must not feel pain because they may continue to mate whilst being consumed by the female. I finish with thoughts about the idea that because robots may be constructed to act as if they experience pain, the argument that animals might experience pain is diminished.