small creature in my tank

[Joe V]

I have a 20 gallon long tank with 7 ember tetras, shrimp, and two bristle nose pleco.  The tank has live plants.  What are these flea looking creatures and how can I get rid of them.  There are so many of them living in the tank.  Some have managed to get into my 75 gallon I guessing from moving plants around.  The problem is not so bad in the 75 gallon I am assuming due to larger fish and the team of Cory's.  Any help is much appreciated.

[Biotope Biologist]

Amphipods they likely hitch hiked from the live plants