This is a cave glow worm. 这是一种洞穴萤火虫

16. alongside hundreds of others.
    边上还有好几百根
17. Beautiful though these threads are,
    虽然这些丝看起来很漂亮
18. they have a sinister purpose.
    它们却是阴险的陷阱
19. This is a cave glow worm.
    这是一种洞穴萤火虫
20. To trap its prey it goes fishing with a line of silk.
    它利用一根根的丝来诱捕猎物
21. The silk comes from glands in the glow worm's mouth
    丝产生自萤火虫口中的腺体
22. and is loaded with droplets of mucus.
    上面缀着一串粘液滴

来自《行星地球 第一季 第四集 Planet Earth S01E04 洞穴》第 19 行