1. The problem statement, all variables and given/known data You put an anode and a cathode on two different sides of a container fulled with water and paramecia. When you start the current (1,5V), the paramecia "swim" to the negative pole- cathode, where they appear to be unharmed and continue to swim about locally. When you switch the cathode with the anode, they die. Question1: Why do they move? Question2: Why do they die? optional question:If my memory serves me right, the bubbles only appeared on the cathode during the experiment. Is this supposed to happen or did I just forget? 2. Relevant equations 3. The attempt at a solution Apparently this is galvano/elecrotaxis? The bubbles that appear on the cathode are hydrogen molecules, and the ones on the anode are oxygen molecules. If this is electrotaxis then there must be something beneficial where they are migrating or something threatening where they are migrating from? Or is this just a response to the electromagnetic field and the movement is out of their control? Thanks and hello (I'm new :P).