From about 14 months old, the young giraffe leaves the nursery and the surveillance of mothers, to join the group of young individuals. Their size, the size and the hairs at the tips of the males' horns and the color of the fur helps to estimate their age. Young giraffes also engage in forms of collective and mutual delousing. Giraffes reach sexual maturity in their fifth year and live between 20 and 25 years