Substance P

Wendy sends a great little story about naked mole-rats (the picture is adorable, but really mostly it would make an excellent premise for a science-fiction novel--I love the notion of a distinction between chemical and mechanical pain, I had never thought of it in those terms before!):

Researchers have added to the list of biological curiosities about mole-rats: the animals do not feel all types of pain. The discovery could eventually help humans who are battling chronic discomfort.

African naked mole-rats (Heterocephalus glaber) are unusual creatures — they are cold-blooded mammals, have a long lifespan, and live in co-operative societies of hundreds of individuals in a manner more typical of bees and wasps than moles or rats.

The animals react normally to the mechanical pain caused by pinching and prodding, but are insensitive to a suite of other normally nasty stimuli, according to Thomas Park of the University of Illinois at Chicago, Gary Lewin at the Max-Delbrück Center for Molecular Medicine in Berlin, Germany, and their colleagues.

Those stimuli include acid and capsaicin, the ingredient in chilli peppers that causes a burning sensation in many animals. These mole-rats are also odd in that their skin, when inflamed, does not become hypersensitive when exposed to unpleasantly hot objects, even though they react to excessive heat in the same way that other mammals do, the researchers report in PloS Biology

It is purely irrational, but I am consumed with the notion of how appealing it would be to have a huge cooperative society of naked mole-rats living somewhere nearby, perhaps not actually in a back garden (I am too lazy to garden!) but within walking distance...