There is a paucity of information on whether and how the composition of formulas fed to infants influences their short-term feeding behaviors during the first few months of life. The purpose of this study is to investigate whether the composition of infant formula affects infants' feeding behaviors, in particular, how much formula is consumed within a given feed (i.e., measure of satiation) and how much time elapses after the feed until the infant exhibits signs of hunger (i.e., measure of satiety). The investigators will also examine the relationship between the composition of infant formula consumed and infant temperature, activity, sleep, and mothers' perceptions of infants' intake and regulatory behaviors.