Complex sentence: The woodworm is left out of the ark, just like the other "impure" or "insignificant" species; but a colony of woodworm manages to enter the ark as stowaways and thus to survive the Great Deluge.
Split into simpler sentences: The woodworm is left out of the ark, just like the other "impure" or "insignificant" species. However, a colony of woodworm manages to enter the ark as stowaways and manages to survive the Great Deluge.