Small white critters

[RubyU235]

Noticed these little guys on a few of my corals. Any clue what they are, and are they a nuisance?

can anyone tell me if this is a sign of light damage?

 

[tankstudy]

They appear to be pineapple sponges. They aren't too big of a concern.

 

[EeyoreIsMySpiritAnimal]

I can't tell what is in the last pic, but everything else is a sponge. Most look to be pineapple sponges. Perfectly harmless.