At a convention of biological scientists one researcher remarked to another, "Did you know that in our lab we have switched from mice to lawyers for our experiments?"
"Really?" the other replied. "Why did you switch?"
"Well, for three reasons: First, we found that lawyers are far more plentiful; second, the lab assistants don't get so attached to them; and third, there are some things even a rodent won't do. However, sometimes it is very hard to extrapolate our test results to human beings."
