We are new to chickens, and have our first chicks. They are about a week old and I have started teaching them to use a nipple waterer. They have figured out water comes from it, and will peck at it - but only on the side of the nipple, rather than pushing up from the bottom. Any ideas on how to teach them to push up from the bottom? I don't think they are getting anything from pecking at the side of the nipple; however, they keep trying so maybe they are.