Instead, it secretes a glue and USES this to stick bits of sand together to form its casing, in the way that a freshwater caddis fly larva does.

堆沙蠕虫分泌出一种胶状物将沙石粘合在一起形成壳装，这一点类似于淡水石蛾的幼虫。

youdao

Visceral in the sense of strongly worded, rather than relating to the bits of viscera which fly out under the pressure of an alien's claws.

FORBES: Ithaca NY