What are these?

[LBFish]

Today I saw a couple very thin things in my tank that kinda looked like a couple of fine hairs. But then I noticed that both of them appeared to be coming out of these little purple things. I have no idea what they are, but I have seen several others in my tank that look very similar. Any help would be appreciated, and are they good or bad?

Thanks!

 

[XxKnuckleheadxX]

looks like maybe vermited snails. knida blurry though..

 

[SeaBee]

Do they move? Better picture, a little blurry is right. Looks like little snails. I have a hundred of them and they really come out at night.

 

[dcantucson]

Looks like vermited snails to me too. Pretty much harmless.