How do nydus worms cross gaps?

Actually Nydus canals were never specified, so it is assumed that they used some kind of biological teleportation technology. They word worm was never even named in the context.

http://starcraft.wikia.com/wiki/Nydus_canal

They got turned into worms in SC2 development, but at this point the failure to balance them has nerfed them back into basically the same underused building that it was in SC1.

A pity, because they looked incredibly awesome.

 

i figured they just jumped really far in order to cross the gaps.