There may be no amphibians more mysterious than the limbless, burrowing, mucus-covered carnivores called caecilians.

Carlos Jared at the Butantan Institute in São Paulo, Brazil, and his colleagues spent more than a decade studying a shiny greyish-blue caecilian named Siphonops annulatus, observing it in the wild in Brazil’s Atlantic Forest, as well as in captivity. The team reports that mothers coil around their eggs, which hatch in late December and early January. The pale, helpless hatchlings then feed on their mother’s skin and a fluid that she excretes from her cloaca — the combined genital and excretory opening found in amphibians, reptiles and birds.

The authors suggest that studying the elusive creatures in captivity could reveal more about them and inform conservation strategies.