What is this? Leech?

[ShadyBrig]

I recently discovered small worm-like creatures in my aquarium. They are tiny, pinkish and seem to crawl along the glass, rocks, pot and plants. I haven't seem them swim or attach themselves to the fish or snails. I would just like to know if they are harmful, and, if so, then how can I get rid of them. I've tried looking online and at previous posts but I'm still uncertain. Please help.

 

[Mumma.of.two]

http://www.planetinverts.com/what_is_that_bug_in_my_aquarium.html

 

[ShadyBrig]

http://www.planetinverts.com/what_is_that_bug_in_my_aquarium.html

Thanks so much! It seems to be a planaria.

 

[Mumma.of.two]

No problem