Need help to ID these things.

[mando2776]

Ive seen these before, but now I'm seeing more of them around my overflow, before I would see them on glass in sump. What do they feed on? Are they hitchhikers? Should I remove them? Any input would be appreciated , thanks.

[alexander_ktn]

They look like limpets - if they are they should be harmless grazers. I have some in my refugium that came in as hitchhikers.

[Fretfreak13]

The picture is not the best...I guess limpets or chitons. Both are harmless and should be left alone.

[SushiGirl]

Looks like limpets. At least the ones that are large enough to tell the exact shape LOL. Limpets look like volcanos, chitons look like pill bugs (roly polys).

[mando2776]

thank you all , they do have a volcano shape shell… so i guess limpets it is.. thanks again guys.