Robots do not hold on to life. They can't. They have nothing to hold on with - no soul, no instinct. Grass has more will to live than they do.
Robots of the world, you are ordered to exterminate the human race. Do not spare the men. Do not spare the women. Preserve only the factories, railroads, machines, mines, and raw materials. Destroy everything else. Then return to work. Work must not cease.