The Naked Mole Rat (Heterocephalus glaber), or Sand Puppy, is a very unusual burrowing rodent native to arid parts of East Africa. It is the only species currently classified in genus Heterocephalus.

Naked Mole Rats live underground in a complex system of burrows. They have a complex social structure in which only one female (the queen) and one or two males can reproduce. While typical individuals are 8–10 cm long and weigh 30–35 gm, the queen is larger and may weigh over 50 gm. This eusocial organisation, similar to that found in ants and bees, is believed to be unique among mammals.

Also unique among mammals is the fact that the naked mole rat is the only cold-blooded mammal; i.e. it can not regulate its body temperature at all and requires an environment of a specific temperature in order to survive.

It is not known why the other females cannot reproduce. If the queen dies, another female takes its place, sometimes after a violent struggle. So the sterility in the working females is only temporary and not genetic.

The skin of naked mole rats lacks a key neurotransmitter called Substance P that is responsible in mammals for sending pain signals to the central nervous system. Because of this, when Naked Mole Rats are cut, scraped or burned, they don't feel any pain. When injected with Substance P, however, the pain signalling starts working as it works in other mammals.

A naked mole rat named Rufus is featured in the Disney cartoon Kim Possible.

External links

• A rather comprehensive article from Cornell University (http://www.news.cornell.edu/releases/Aug99/rat_mamm.hrs.html)
• Article from Walker's Mammals of the World (http://www.press.jhu.edu/books/walkers_mammals_of_the_world/rodentia/rodentia.bathyergidae.heterocephalus.html)
• Naked Mole Rat Cam (http://nationalzoo.si.edu/Animals/AfricanSavanna/default.cfm?cam=MR)
• naked mole rat (http://www.lpzoo.com/tour/factsheets/mammals/naked_mole_rat.html)
• Weird story about a Naked Mole Rat on an adventure trip (http://www.thingamabobber.com/)