About 30,000 years ago, a squirrel chose a home for itself in Siberia, Russia. Today, the home is 30m below the surface in a layer of permafrost. The squirrel is long gone, but tiny roundworms, a type of nematode have survived in this home. They lasted for all these years, frozen and immobile. Russian scientists have now revived them and are making the worms the first multicellular organisms to have survived being frozen in the Arctic permafrost.