I got this idea from a read aloud I did with my students. I have a girl bathroom pass and a boy bathroom pass. Prior to my use of the thirsty list, the passes were used for both bathroom and drinks. Now, I put out a thirsty list each day and hold on to them for conferences. It helps me keep track of who is out for drinks and how many times a day. You will be surprised to see the same names appear over and over and over again :)!