Menarche. The average age of menarche, or first menstruation, in the United States is 12.88 years for Caucasian girls and 12.16 years for African American girls.A popular misconception is that menarche marks the beginning of puberty; in reality, menarche occurs later in puberty.enarche. The average age of menarche, or first menstruation, in the United States is 12.88 years for Caucasian girls and 12.16 years for African American girls.
Quick Answer. Roadrunners eat insects, lizards, scorpions, small birds, rodents and snakes, including rattlesnakes. During the winter months when its preferred food is scarce, the roadrunner may supplement its diet with fruits, seeds and other vegetable matter. Continue Reading.
Popularized in Warner Brothers Cartoons. The legendary roadrunner bird is famous for its distinctive appearance, its ability to eat rattlesnakes and its preference for scooting across the American deserts, as popularized in Warner Bros. cartoons. The roadrunner is a large, black-and-white, mottled ground bird with a distinctive head crest.