Most caecilians are burrowers, living in a network of tunnels underground. A hard, thick, pointy skull helps these amphibians dig in soft dirt. Because of their underground lifestyle, caecilians have little need to see or hear. Therefore, their eyes are very tiny in some species, or hidden under the skin or skull in other species, making just tiny gray bumps for eyes.
Some species in South America spend their lives in water instead of on land. Caecilians don’t have ear openings, so it is doubtful they can hear sounds the way we do. They rely on their sensitive tentacles, located between the nostrils and the eyes, to locate their prey and find their way around.