All animals have the same basic brain chemicals, like dopamine, serotonin, endorphin, and cortisol. Neurochemicals motivate a body to approach what feels good and avoid what feel bad. Animals don't override these impulses, so they help us understand how our brain chemicals work.
A thirsty elephant surges with dopamine when it finally drinks water, and that wires it to find water in the future. The next time the elephant is thirsty, it walks in the direction that feels good. This works because dopamine is triggered by the sights and smells of water holes past. Conscious effort is not necessary because electricity in the brain flows like water in a storm, finding the path of least resistance. Every neuron active during a dopamine experience gets linked to the well-developed dopamine pathway, so it flows easily in the future. Dopamine triggers a good feeling when an animal meets a need, and paves a pathway to release more good feelings when we see another way to meet a need. The first step of a twenty-mile trek to water is fueled by dopamine, and so is every step after that.