Which is better to be? Wild and free or tame and domesticated? That has always been an interesting philosophical question. Professor Mark Viney and colleagues at the University of Bristol compared the immune function of wild mice who have to find their own food with that of mice bred in captivity who have all food and lodging provided for them. The study found that, by most measures, the wild mice had a greater immune function. It also found that the immune function was substantially more variable among the wild mice.