The ball python (Python regius), also known as the royal python, is a python species found in sub-Saharan Africa. Like all other pythons, it is a non-venomous constrictor. This is the smallest of the African pythons and is popular in the pet trade, largely due to its small size and typically docile temperament. No subspecies are currently recognized. Life expectancy in captivity is as much as 47 years, though such outcomes require regular care and a clean, well-maintained living environment. The name "ball python" refers to the animal's tendency to curl into a ball when stressed or frightened....

In economics, utility is the satisfaction or benefit derived by consuming a product, thus the marginal utility of a good or service is the change in the utility from increase or decrease in the consumption of that good or service. Economists sometimes speak of a law of diminishing marginal utility, meaning that the first unit of consumption of a good or service yields more utility than the second and subsequent units, with a continuing reduction for greater amounts. Therefore, the fall in marginal utility as consumption increases is known as diminishing marginal utility. Mathematically: MU1>MU2>...