If you think about a diabetic, when the blood sugar levels, also known as glucose levels, drop. The body will need Insulin to correct it so the answer will be “insulin”
Th earth scientists have improved our understanding with the environment because of their studies in which they had shown better understanding and explanation of occurrences with the means of having to provide not only explanation nor visuals but also providing proof of these mere existence that made people believe and understand the environment.
Predators are the ones who consume the prey and rely on them as a food source, while prey rely on predators to control their population.