I have 9 month old twins that have a cough but no other symptoms. do i take them to the dr or how can i treat it at home?

Simple measures: If babies are active, happy, and only mildly symptomatic, they may be fine at home. Humidified air may help. Tylenol is sometimes needed for 1-2 days. Otherwise, a pediatrician can evaluate. Such coughs are usually viral. Much less likely, they are bacterial. Viruses like RSV, Parainfluenza and Influenza can hit babies pretty hard. Be sure no vaccines were missed (such as pneumonia and flu shots).