Hermit crab realtors hate this guy...
"For humans, pain is a powerful motivational driver, and we go to great lengths to avoid it. But we also can override our instincts and choose to endure it if the rewards are great enough. We suffer the dentist’s drill for the long-term benefit, for example. What would a crustacean want badly enough to make it endure pain?
For hermit crabs, it turns out to be a good home. These animals take up residence in abandoned seashells, but they can be made to give up their home if given a shock inside the shell. Elwood found that the likelihood of a hermit crab’s dumping its shell when given a shock depends not only on the intensity of the shock but also on the desirability of the shell. Crabs in better shells took bigger shocks before they were willing to move out. This suggests that the crabs are able to weigh different needs when responding to the noxious stimulus. Once again, this behavior goes far beyond reflex, Elwood says.
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"Unlike crustaceans, insects seem to have no pain-related behaviors. If an insect’s leg is damaged, for example, it does not groom or try to protect the limb afterward. Even in extreme cases, insects show no evidence of pain. Imagine a praying mantis eating a locust, Smid says. With its abdomen opened up, the locust will still feed even while being eaten."
https://www.washingtonpost.com/national/health-science/do-lobsters-and-other-invertebrates-feel-pain-new-research-has-some-answers/2014/03/07/f026ea9e-9e59-11e3-b8d8-94577ff66b28_story.html
"For humans, pain is a powerful motivational driver, and we go to great lengths to avoid it. But we also can override our instincts and choose to endure it if the rewards are great enough. We suffer the dentist’s drill for the long-term benefit, for example. What would a crustacean want badly enough to make it endure pain?
For hermit crabs, it turns out to be a good home. These animals take up residence in abandoned seashells, but they can be made to give up their home if given a shock inside the shell. Elwood found that the likelihood of a hermit crab’s dumping its shell when given a shock depends not only on the intensity of the shock but also on the desirability of the shell. Crabs in better shells took bigger shocks before they were willing to move out. This suggests that the crabs are able to weigh different needs when responding to the noxious stimulus. Once again, this behavior goes far beyond reflex, Elwood says.
...
"Unlike crustaceans, insects seem to have no pain-related behaviors. If an insect’s leg is damaged, for example, it does not groom or try to protect the limb afterward. Even in extreme cases, insects show no evidence of pain. Imagine a praying mantis eating a locust, Smid says. With its abdomen opened up, the locust will still feed even while being eaten."
https://www.washingtonpost.com/national/health-science/do-lobsters-and-other-invertebrates-feel-pain-new-research-has-some-answers/2014/03/07/f026ea9e-9e59-11e3-b8d8-94577ff66b28_story.html