The motivation thirst
In order to survive, an organism not only has to control their food intake but also their water intake. This is the cause for water being a strong motivation (for certain behavior), we cannot live without water for more than a few days.An organism can replenish its water deflict in two ways:
1. It can add water to his body by drinking
2. It can recover water from the kidneys before it is excreted as urine.
After a night's sleep your urine has a darker color because the body has recovered water from the kidneys to compensate the fact that no water was consumed while sleeping.
