I found this definition:
The Cattle Egret, (Bubulcus ibis), is a small white heron.
The Cattle Egret is often found in dry grassy habitats, unlike most herons which are associated with shallow water. It feeds on insects, especially grasshoppers, and is usually found with cattle and other large animals which disturb small creatures which the egrets then catch. This species will sometimes ride on the backs of these animals.
