At 09:40 PM 1/31/00 +0100, Paul wrote:

>Just read today of another medical research using rats and made me think why
>people in laboratories use rats?

Rats are mammals, breed quickly, and are inexpensive.  Generally, what will
kill a rat will kill a human.  Most importantly, however, is the purity of
rats.  I believe the breed is the Norweigan Black, which is a white rat,
not a whole lot larger than a large mouse.  This breed is genetically pure.
 That is, if you do an experiment with a rat this year.  And then do the
experiment again in 10 years time on the same pure species, then you are
guaranteed to have an identical experimental "platform".  The
reproducability of results makes the rat indispensable.

Remember, the leading cause of death in lab rats is lab assistants.

James at Penn State