Why does my newborn always seem hungry?

babies are smarter than adults they know when they are full!!somtimes when babies have an upset stomach they try to suck because they dont know why there stomach is hurting but they know when they get that pain they are hungry so try burping him more!!and somtimes when babies have an upset stomach giving them there pacifier can help them suck and the pain will go away!!both my kids got really upset stomachs after they ate and with my daughter she was addicted to her pacifier