The eggs hatch into transparent larvae which were once considered to be a separate species to the adult eel. Indeed Aristotle thought eels were born from earthworms. The larvae spend three turbulent years swimming and drifting with the Gulf stream currents, until they reach the coasts of Europe. When they reach British waters they are only 6cm long. The larvae enter European inland freshwater, darken in colour and are known as elvers.
Elvers eventually enter rivers where they head upstream and develop into adults.
Sand Eels Adult eels can grow over 40cm, they can survive out of water for up to four hours and can even travel over land. Adult eels feed on small crustaceans, worms and insects to grow up in 10 to 14 years to a length of 60 to 80 cm. Fascinatingly, some people think the Loch Ness monster is a giant eel. Literally billions of elvers migrate through Britain's rivers in the springtime. Here they doggedly pursue their predestined path, and little can stop them.