Web forming on zoos

[coolcat310]

What does it mean when a web-like substance starts forming in your zoos? I just bought some zoos from the LFS a day ago, now it's forming some web-like substance on parts of the zoos.

Thanks,

coolcat310

[RicksReefs]

theres a worm (forgot the name) that
i've seen & experienced that frequent
the same habitat as zoo's, it releases
a web to catch floating debri, reels it in
& munchs on what it caught. fairly harmless
critters.
HTH