Why shoo away the mother bird before taking her eggs or chicks? The Torah doesn’t say why we are commanded to do this. There is a major school of Jewish thought that regards this omission as being quite deliberate. This is the school that produced the Mishnah’s teaching prohibiting a person from praying, “God, have mercy upon me just as You have mercy upon the bird in its nest.” This school presumes that God’s laws have no known rationale, and that we observe them simply in order to do His will. It argues that it is pretentious of us to assume that God is having mercy upon the mother bird, and by extension that feelings of compassion when performing this (or any) mitzvah would be misplaced.