Any raw meat. I see your an airgunner, shoot some squirrels and pigeons for it. Rabbits the natural diet but they love pigeons, squirrels and so on too. Dont bother with crows etc. I wouldnt feed rats to mine neither, filthy f*****g things! And feed whole, dont skin. Gut yes if you want to but leave the offal in. As for training: you shouldnt have to, a ferrets instinct is to explore a dark hole that smells of rabbits and when they find a rabbit their instinct is to try n kill it. The rabbits instinct is to get outa here! Lol! If it does seem a little slow off the mark let it follow an experie