Some South American species 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. Scientists have found that an organ in their ear picks up vibrations from the ground to help them detect predators and prey. Caecilians also use their sensitive tentacles. These are between the nostrils and the eyes and help caecilians find food or their way around.

They may look soft on the outside, but inside a caecilian’s mouth are dozens of needle-sharp teeth. The teeth can grab worms, termites, beetle pupae, mollusks, small snakes, frogs, lizards, and even other caecilians! All food is swallowed whole. Caecilians have toxic glands in their skin that sometimes protect them from being eaten by other animals.

Like salamanders, caecilians produce young in two different ways, depending on the species. Some female caecilian species lay eggs in damp holes near water. When the larvae hatch, they have gills and a short, finned tail to help them swim in the water as they feed on plankton. Through a series of changes, a single lung replaces their gills. Their skin becomes thicker, the annuli develop, and sensory tentacles appear. At this point, the newly developed adult moves to the land and goes underground.

Some species give birth to live young that are fully developed inside the mother before they are born.

Imagine—there are over 120 species of these animals, some as long as we are, that number in the millions on at least 4 continents. And almost no one knows they’re there, let alone ever sees one! That’s probably why almost nothing is known of caecilians’ habits and lifestyle. We still have much to learn about this unusual amphibian!