Fully agree, Supersprout. I also found that if I germinated broad beans and peas in damp kitchen paper and a plastic bag in the airing cupboard, and sowed them as soon as the root began to appear, the mice left them alone. According to some, the taste of a germinated legume is not as pleasant as one before it germinates. This is slightly less trouble than growing them into plants in guttering, then transplanting, though I have tried that too. All around me on plot one last year, neighbours had rows of neat little holes across their plots where the mice had removed their beans.
Having said that, I have just sown ungerminated broad beans in my new plot where I don't think (touch wood) that the mice have yet discovered allotments to be a source of food, as there are so few of us on a big site and no-one else grows broad beans.