At the beginning of the 20th century, doll makers offered dolls that looked and felt like infants. Prior to the availability of these new dolls, girls had dressed, tea-partied with, and played with what we would call toddler dolls or companion dolls. Infant dolls, however, encouraged nurturing play in which girls practiced motherly duties. As the 20th century progressed, infant dolls took on sophisticated life-like features. The 1930s produced drink-and-wet dolls. Infant dolls made later in the century cried, talked, ate, crawled, played peek-a-boo, and even responded to a child's voice. More recent dolls detect motion and move and talk when their mama comes near.