She leads the pack-train, and where she stops the mules gather around her while waiting for the men to come and relieve them of their burdens.

Sometimes a horse may serve as a leader, but a mare is surer of gaining the affection of all the mules in the train.

This is an important fact for travellers to bear in mind if they use mules at all.

In daytime the train will move smoothly, all the mules, of their own accord, following their leader, and at night keeping close to her.

In this way she prevents them from scattering and becomes indispensable to the train.
But in spite of the vigilance of the sabana and the advantage of a good yegua, it may happen, under favourable topographical and weather conditions, that robbers succeed in driving animals away.