What do hispanic kids put on the doorstep on January 5 and why?

On the night, of January 5, the figurines of the Three Wise Men are added to the nativity scene. Before going to bed the children place their old shoes under their bed or in the living room, where the Wise Men will leave them their presents. Some also place outside the house, some hay and a bucket with water for the animals, and even some cookies and milk for Melchor, Gaspar and Baltasar.