I put some temporary fencing up around my container garden because the tops of my carrots kept disappearing. I suspected rabbits. It was not rabbits. Shortly after the leaves came back, they were gone again, despite the heavy wire guarding them. Maybe grasshoppers are the culprits. I don't think I will be getting any carrots this year, although they valiantly keep trying to produce leaves. (Yes, I'm growing them in a feed bag, which isn't very deep, but they are globe carrots, so they don't need depth. But leaves would be helpful.)

Carrot tops devoid of leaves