Collecting saliva is an easy, non invasive way of gathering information about you and your baby. We collect saliva to look at changes in hormones. These hormones are naturally-occurring substances in the body that change with time of day and excitement level. To measure them, we will collect several samples of saliva throughout the visit - generally before and after your play session. We use specially designed, very small, tasteless sponges to collect the saliva directly from your or your baby's mouth. The sponge will then be placed in a container to be frozen for later analysis.