The correct answer is option 1: snakes. Snakes do not have eardrums. Eardrums, also known as tympanic membranes, are thin membranes that vibrate in response to sound waves and transmit them to the inner ear. While most animals have eardrums, snakes have a different way of detecting sound. They have a specialized structure called the columella, which is a bone that connects the inner ear to the jaw. This bone picks up vibrations from the ground and transfers them to the inner ear, allowing snakes to sense vibrations and perceive sound. So, even though snakes do not have eardrums like many other animals, they have adaptations that allow them to detect and interpret sound in a different way.