wha is the name of the movie about a guy who goes to alska to study wolfs and lives like them and eats mice?

Answer 1

...you're talking about the humorous and dramatic true-life adventure, from 1983, entitled "Never Cry Wolf"; director Carrol Ballard has a penchance for directing breath-takingly visual motion pictures (..."The Black Stallion", "Wind", "Fly Away Home", etc), and "Never Cry Wolf" is no exception...

...a bit of irony, here: as you mentioned, there's a part of the film, where the the main character, in studying the wolves, figures out that instead of killing the local caribou, as was scientifically suspected, they were instead devouring hundreds of field mice. In testing this theory, he himself, assumes a diet of eating nothing but mice; the irony here, of course, is that "Never Cry Wolf" was produced by the folks over at Disney, who...uh, maintains a certain mouse spokeperson and representative....

Answer 2

Never Cry Wolf-Disney movie. Excellent!

Answer 3

Eight Below?
Snow Dogs?