The rabbits’ long ears serve two main functions. The first is so they can catch sound from any direction. Rabbits can move their ears independently so they can hear in two directions at once.
The second is that they give off heat from the body through a vast network of blood vessels to keep the bunny cool, since these animals can’t sweat or pant. However not all rabbits have big ears – some domesticated breeds like the Netherland Dwarf have short ones.