Ahiṃsā is a central ethical principle of the Hindu, Buddhist and Jain traditions, and the first of the restraints of classical Yoga. Jainism carries it furthest, to the protection of the smallest creatures. Gandhi made it the basis of his politics of non-violent resistance.
Ahiṃsā
Non-harming: the principle of not injuring any living being, in thought, word or deed.
Also: Ahimsa, non-violence