Bug in tank

Question
My tank has been set up for 3 years and I have had fish tanks since I was a kid.  I have never seen this before.  I have mainly tetras in the tank but recently bought some platties. It is a 20 gallon tank there is a total of 16 fish and a frog. There are live plants in the tank. (Which is new for me.)  The other day I notice little green skinny spots as I was looking I notice them moving.  They are above the water line. What are they? Are the harmful to the tank? How do I get rid of them?  Thank you for your time and help.   Kellie

Answer
Hi Kellie;

Probably just a pond critter that came in with your plants. Most of these organisms do not bother the fish at all, especially since they appear above the water. If they did, you would most likely see them on the fish too.

If you have a way to get a photo of them it would be helpful. Let me know and I can give you a link to email it to me.

At Your Service;
Chris Robbins