The lobster's nervous system has been extremely well-studied because it serves as a "simple" model of neural circuitry in something less complicated than the highly cephalized vertebrates. Lobsters do not possess any kind of receptor akin to our pain receptors. However, they do possess stress receptors. It is not known whether they possess any kind of temperature sensitivity, although each species is adapted to live in a certain range of temperatures and will eventually die if forced to live beyond its normal temperature range. Scientists have not discovered how a lobster's "brain" processes sensory information from cuticular stress or temperature, so we cannot say for sure if they feel pain or not. Many people have debated how to "humanely" kill a lobster with ideas ranging from electrocution to freezing before boiling (though that also exposes them to an unpleasant temperature and it takes some time before they die). The general consensus is that death is most rapid - - and, if they do indeed "feel" something, it is only momentary - - if they are placed into a boiling pot of water.