ID Verification: Brown Colonial Hydroids?

[Dwise]

Hello all,

I recently just finished cycling my tank when I noticed these bunch of small "things" with tentacles. I thought it was babies of the feather duster worms I have but looking up common hitchhikers on the web leads me to believe they are hydroids. Right now they are only on one rock as far as I can tell but I am starting to get bummed out. I bought this live rock from someone who recently broke down their tank. I thought it was safe because they said they "cured" the rock for 5 weeks and "never had any problems".

Anyways, I just want a verification on these as I am new to the hobby.

 

[ReefSafeSolutions]

Maybe aiptasia? If someone else confirms that it is aiptasia, don't get bummed out, looks like you could cover them with some putty and nip it in the bud.

[jimmyree]

Maybe aiptasia? If someone else confirms that it is aiptasia, don't get bummed out, looks like you could cover them with some putty and nip it in the bud.

Yup, aiptasia.

[GoingPostal]

The brown hydroids I've dealt with had a stalk and would retract into it, do these do that? Superglue or potty over them, I didn't have a problem with them bothering corals but they will spread and be ugly.