Olds and Milner constructed new experiments that allowed the rats to press a lever. Each time the lever was pressed, an electric current stimulated the pleasure centers of the rats' brains. The rats would go into a pleasure-seeking frenzy, pressing the lever as many as 2,000 times an hour. They would ignore food and water, working themselves into a state of exhaustion and starvation. Eventually, they would die. They literally pleasured themselves to death.