Current known or inhabited Earths are many and not all specifically named in the Worm Universe.
Earth Bet is the main location of the story. It is the home world to Taylor and the majority of the other capes in the story.
Earth Aleph is the home to the Travelers. It is a world that diverged paths from the time of Scion's first appearance. This world has variations of everyone born before said appearance though anyone born thereafter may not have a duplicate in Earth Bet.
Earth Gimel is an alternate Earth connected to Brockton Bay. It is used to evacuate for much of the East Coast.
Earth He is an alternate Earth used to evacuate Western Europe and Northern Africa minus the English speakers.