Do you know the cattle egret (Bubulcus ibis)? Unlike other herons, cattle egrets are stocky. They have relatively short, thick necks and sturdy bill.

Additionally, they don't like to prey on fish like other herons do. Instead, they prefer to follow their old friends, the buffalos, and peck at insects disturbed by the plowing.

There is an old saying that friends always help each other. For buffaloes, cattle egrets are more than just hitchhikers. The cattle egret removes ticks and flies from buffaloes' back, acting as "back cleaners" and guards.

Sometimes, there will be two cattle egrets on a buffalo, one on the left and one on the right, just like the "left and right guardians" of the buffalo. The "friendship" of the three has become a little crowded, so when other cattle egrets want to join them, they will work together to expel the fourth one.