Nature has accoutred rabbits with ears not just as a hearing mechanism but also as a means of protection as it allows them to avoid danger even before they encounter it. Even though rabbits are timid in size and look vulnerable and innocent with respect to their physical appearance, they have a great many enemies. This fact calls for an extremely strong defence mechanism that enables the rabbit to catch even the slightest hint of danger. Acting like old-fashioned sound ear-trumpets, their ears have the power to catch a great many sound waves, this ability equipped in the large part of the ear that later on channels the sounds in the rabbit's ear directly. Besides having an extremely sharp sense of audibility, rabbits are also great runners and have a keen sense of smell. Long back legs enable the last quality making them cover great distances in short periods of time, thus managing to save them from the enemy.
Rabbits have large ears to help them hear their predators coming even before they get there. (which most people know.But they also help to keep them cool,but few people know that)..hope that's helpful.
To allow them to hear danger coming.
Because they are a prey animal and having acute listening is a survival mechanism.
Because in nature rabbits are a species who have a lot of prey. So by having large ears they need to know what is going on around them, they also need good hearing as they don't have very good sight.
A rabbits large ears help them in escaping predators.They have very acute in hearing.
It helps them hear their predators and good eyesight helps