Well I had a google around Robin at all my favorite rat sites and I can't find anything specifically against rats eating figs so likely it's fine. As with any new food, just give it as a treat and see how they do with it. Rats, unlike a lot of other rodents, are very careful of new and unknown foods so generally won't do more than nibble at it carefully at first anyways (well except for some like my piggie girl Stubby who is basically a stomach with some other limbs and a head attached LOL).