Whether lobsters, crabs and other crustaceans can feel pain has been a point of debate for years. For the lobsters and crabs that we eat, cooking the creatures while they are still alive overwhelmingly yields the best taste, and cooks often accept with selfish convenience that the creatures feel no pain as they are being boiled alive.

But a series of experiments by Queen's University Belfast animal behavior researcher Robert Elwood presented Wednesday to the Behavior 2013 conference in Newcastle, UK, suggest that crustaceans do indeed experience pain.

Elwood's experiments were published in 2013 and 2008, but he presented the findings in tandem at the Behavior conference, according to the Nature blog.

Crabs, lobsters, prawns and other crustaceans are generally not afforded the protection of animal welfare laws, even though huge numbers of them are farmed or caught for human consumption.

Part of the reason crustaceans are not given the same welfare considerations as other farmed animals is the widely-held belief that the creatures cannot experience the "unpleasant feeling" that we refer to as pain. And by cramming them into a pot, putting a lid on it and turning the fire on high, it's likely that the creature's comfort is the last thing on our minds before we eat them.

Elwood's previous research has showed that prawns and hermit crabs respond to electric shock with a reaction consistent with pain. His most recent experiment built on his prior work on pain in crustaceans.

"The experiment was carefully designed to distinguish between pain and a reflex phenomenon known as nociception. The function of pain is to aid future avoidance of the pain source, whereas nociception enables a reflex response that provides immediate protection but no awareness or changes to long-term behavior," he said in a January 2013 statement.

"While nociception is generally accepted to exist in virtually all animals the same is not true of pain. In particular, whether or not crustaceans experience pain remains widely debated."

To ascertain whether crustaceans experience pain, he devised a system to test shore crabs (a species very similar to the ones commonly on dinner plates) where some 90 crabs were individually presented with two dark shelters and upon entry some of the crabs were given an electric shock. After waiting for a set period of time, the crabs were presented the same situation and some of them again were shocked. As Elwood continued the procedure, he documented the crabs' reactions.

"Having experienced two rounds of shocks, the crabs learned to avoid the shelter where they received the shock. They were willing to give up their hideaway in order to avoid the source of their probable pain," he said.

In discussing his experiments with the Newcastle meeting, Elwood said, "Assessing pain is difficult, even within humans," but he that there is a "clear, long-term motivational change [in these experiments] that is entirely consistent with the idea of pain."

The animal rights group PETA cites invertebrate zoologist Jaren G. Horsley on its entry on lobsters and crabs. 

"As an invertebrate zoologist who has studied crustaceans for a number of years, I can tell you the lobster has a rather sophisticated nervous system that, among other things, allows it to sense actions that will cause it harm."

In his renowned 2004 essay "Consider the Lobster," writer David Foster Wallace thoroughly reported on the crustaceans and their consumption at the 2003 Maine Lobster Festival, noting the absurdity behind boiling something alive to eat it.

"A detail so obvious that most recipes don't even bother to mention it is that each lobster is supposed to be alive when you put it in the kettle ... Most of us have been in supermarkets or restaurants that feature tanks of live lobster, from which you can pick out your supper while it watches you point. And part of the overall spectacle of the Maine Lobster Festival is that you can see actual lobstermen's vessels docking at the wharves along the northeast grounds and unloading freshly caught product, which is transferred by hand or cart 100 yards to the great clear tanks stacked up around the Festival's cooker-which is, as mentioned, billed as the World's Largest Lobster Cooker and can process over 100 lobsters at a time for the Main Eating Tent."

He goes on to cite the Main Lobster Promotion Council, which reported: "The nervous system of a lobster is very simple, and is in fact most similar to the nervous system of the grasshopper. It is decentralized with no brain. There is no cerebral cortex, which in humans is the area of the brain that gives the experience of pain."

Wallace continues:

If you're tilting it from a container into the steaming kettle, the lobster will sometimes try to cling to the container's sides or even to hook its claws over the kettle's rim like a person trying to keep from going over the edge of a roof. And worse is when the lobster's fully immersed. Even if you cover the kettle and turn away, you can usually hear the cover rattling and clanking as the lobster tries to push it off. Or the creature's claws scraping the sides of the kettle as it thrashes around. The lobster, in other words, behaves very much as you or I would behave if we were plunged into boiling water (with the obvious exception of screaming). A blunter way to say this is that the lobster acts as if it's in terrible pain, causing some cooks to leave the kitchen altogether and to take one of those little lightweight plastic oven timers with them into another room and wait until the whole process is over.

Robert Hubrecht, deputy director of the Universities Federation for Animal Welfare and the organizer of the session at which Elwood spoke, told Nature that the data for crustaceans appear equivalent to the kind of data that are used to give mice the benefit of the doubt, and thus award them protection from possible pain under the law.

"We're behaving in an illogical way at the moment by protecting mice but not crustaceans," he said.