What type of flat worm ?

[Vincent100]

Hi all
These flat worms showed up today on my sump glass
Tried to get clear pics but was hard with my phone
Anyway can I get a ID please and should I be getting them out ASAP
Sorry about all the pics didn't know which was best so you got the whole lot haha

Thanks

 

[PaReeferJ]

I had those guys in my sump a little while back. One day they just disappeared and never came back. I didn't change anything or suck them out.

 

[Lionfish Lair]

It's a common acoel flatty.

 

[Vincent100]

Thanks reeferj and lionfish
Should I remove or just let them be ?

 

[PaReeferJ]

I just let mine be. Didn't hurt anything in my tank.

 

[Lionfish Lair]

I too would leave them be.