Mice Versus Lawyers

At a convention of biological scientists one researcher remarks 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 four very good reasons. First we found that lawyers are far more plentiful, second, the lab assistants don't get so attached to them, third there are some things even a rat won't do, and fourth sometimes it very hard to extrapolate our test results to human beings.