my 2 year old regular corn snake has a very odd appetite. he refuses to eat for 7 weeks on end and then eats like a pig. i had him checked out by a vet and i know that it isnt because of shedding....he seems to be okay now but every so often he gets extremely thin. he is also very picky - he eats frozen mice but he only accepts the grey and white ones. he won't eat the black ones or others he deems "not right" do u guys think he is sick in some way or is he just stubborn? pleaz write back