"In debates regarding whether insects and other invertebrates can feel pain, conflicting evidence can be raised on either side. For example, it seems clear from many studies that invertebrates can learn to avoid electric shock, heat, certain chemicals, and so on. Meanwhile, there are examples of invertebrates apparently unconcerned by physical injury. In my opinion, this collection of evidence suggests that invertebrates plausibly suffer in response to some stimuli but maybe not others. If so, it seems useful to further explore which particular stimuli are unpleasant to invertebrates to what degrees, in order to inform ethical treatment of invertebrates."