There is a theory which states that if ever anyone discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.
There are three reasons why lawyers are replacing rats as laboratory research animals. One is that they are plentiful, another is that lab assistants don't get so attached to them and the third is that they will do things that you just can't get rats to do.