I give 'em a bit of everything (all raw&fresh) rabbits, squirels, trapped mice & moles, fish, molluscs etc....
But also dry ferret food mixed with some catfood (1:1) in time of lack of carcass (in summer when flies are a problem)
I was told to be careful with too much organ meet (liver/kidney) because it can cause a toxic build-up of Vit-A (paralysis)
I let mine loose in the garage now and then, and one crunched up a fat hybernating frog (I think they are protected so its probably against the law to feed them!)
They also seem to love them nasty munching (crushed) snails (b