No, rabbits probably shouldn't eat fiddleheads. Although they are not listed on the list of known poisonous plants for rabbits (see link below), raw fiddleheads are known to be poisonous to humans, so they could be for rabbits as well (see link below). See the related questions below for more info about what rabbits can eat.
Camas root, fern fiddleheads, wapato
Most animals avoid ferns because the mature fronds are poisonous. Humans and most farm animals like cattle, horses, pigs, etc. will get sick if they eat mature fern fronds. White-tailed deer, rabbits, and European wood mice are a few animals that can eat ferns. They usually eat the soft new shoots (called "fiddleheads") that aren't poisonous yet. Humans also eat fern fiddleheads in some parts of the world, usually after cooking them.
You will see fiddleheads in the first stage known as transition in the life cycle of a fern. The fiddleheads are delicately divided when they expand into fronds.
yes!foxes do eat rabbits
Man (carnivores) may eat rabbits, but rabbits (herbivores) eat plant life.
The impala is herbivorous; it does not eat rabbits.
rabbits don't eat animals they are vegetarian's.
rabbits can not eat lemons.Lemons are to sour for rabbits.
it is rabbits
fiddleheads
Rabbits are herbivores and do not eat other rabbits! They only eat plant material, fruit, pellets, and vegetables.
No rabbits eat their feces, although all rabbits eat cecotropes. Rabbits have two kinds of droppings: feces, and cecotropes. Baby rabbits that aren't weaned yet eat their mother's cecotropes; once they're weaned, they eat their own cecotropes.