Sometimes it is possible to find happiness through knowing correctly what is to be done and what is to be abandoned, many sentient beings confuse the causes of suffering with the causes of happiness. For example, out of her caring, a mother bird kills countless worms and insects in order to feed her chicks, but this accumulation of negative actions, lifetime after lifetime means that the mother bird moves further and further away from a fortunate rebirth. Mothers have done so many negative things for the sake of their children and consequently continue to wander in samsara.

-- His Holiness the 17th Karmapa, Ogyen Trinley Dorje