"humans ingest proteins to build muscle and connective tissues and to form enzymes and antibodies. why do we consume carbohydrates? "

In humans, proteins form the structural as well as plays the functional role like as a catalyst but a human diet requires 50-55% carbohydrate.

This accounts for the reason as the carbohydrates form like glucose is oxidized or broken down which provides energy to perform various functions.

The human metabolism is programmed in a way that it first utilizes glucose as a reactant instead of other sources like proteins in cellular respiration to form ATP molecules.

This shows that carbohydrate is the primary source of energy to the human and thus consumed by humans in the large amount.

answer: decrease

a limiting factor is the one which decrease the abundance, distribution and causes extinction of the population of species in a ecosystem. here, predators including hawks, owls and snakes are the limiting factor for the population of mexican free tailed bat.   although bats are nocturnal animals as they forge for food at night these predators also may remain active during night which can decrease the population of the mexican free-tailed bats. also, these bats eat only one type of insects that are moths. the food can also be a limiting factor as all 400 members are dependent upon same type of food needs that are moths. the decrease in the moth population can cause decrease in population size of the mexican free-tailed bats.

therefore, the scenarios will most likely to decrease the population size of the mexican free-tailed bats.