You may kill them using attack glyphs. Which is slow (they do much less damage to Worms than to your usual enemies). But it works.
You can also use Web glyph and place a web on predators roaming the Worms' chambers. Pay particular attention to the Worm (just "Worm", the one that looks like a giant worm). He tears apart all predators that stay in his way. If any of the predators with you Web on was caught in traffic, the damage is not dealt.
Only the predators that are being eaten can damage a worm (if they are "webbed"), and this one isn't any different.
