I was under my 125g tank and noticed that I have worms in the tank!!! Not really sure where they came from, but, I need to know if they are harmful in any way, or are they okay. I saw three speerate ones, there could be more. If I need to get rid of them, how do I do it? I have 8 different fish, a bunch of snails, and hermit crabs. Can the worms stay too??