In small intestine water is extracted from digested food.
According to the second law of thermodynamics, energy is never 100% efficient because some of the energy disperses as heat.
Babies, especially those who are at least 4-6 months old, have the tendency to explore objects by touching and holding them, and putting them in their mouth. By this time, it is very important to keep small objects out of their reach so that accidents can be prevented.
They study and do lots of research