I had this bad during two of my pregnancies. I would crave ice so bad, I'd practically drool when I was around it. It was nothing for me to crunch through cup after cup of ice. I also couldn't get enough of the smell of a freezer, it was really weird. Turns out it's just an iron deficient thing, but for some reason taking iron didn't help that much. Soon after I had my babies, it went away. Normally I can't stand to crunch ice!