Is this a feather duster?

[Exotic Aquaria]

So these little guys popped up about a week ago. As of right now I have three of them that have borrowed into empty snail shells. Are these baby feather dusters or something I should be concerned with.

 

[Crabs McJones]

Looks to be

 

[nautical_nathaniel]

Yup, looks like a little feather duster perfectly harmless filter feeders.

 

[Exotic Aquaria]

I was hoping they were although I have no idea how they got in my tank