A matriarchical elephant herd walks up-stream to bathe, wallow in the mud, and drink. All family herds are led by a large, elderly female. The other females are usually all related to the matriarch, i.e., sister and younger females who help raise and protect the smaller members and babies. There may be young males who contribute to the care in the herd, but they are usually driven out when they reach approximately 8 years oif age. [Big Tom's, Hwange NP, Zimbabwe].