I have my first flock of chickens, 3 RIR and 3 BR that are currently 18 weeks old. We switched them to the water cups(red ones with the yellow stick they peck). I am concerned they won't figure out how to use it. We have seen some of the chickens use it, but not all of them. Should I be doing something to help or will they be ok? We have raised these chicks since they were 1 week old and haven't lost a one, so I am paranoid to do something wrong now!