This model shows an ecosystem with four trophic levels or predators and prey interacting. The four organisms are grass, rabbits, dogs, and birds. The sliders allow for adjustment of birth and death rates of all three animals to test how those values affect the populations when the model is run. The soil fertility slider changes the amount of grass in the model, because more fertile soil means that more grass can grow. Another limiting factor is the hunting rate. When hunting is turned on, the slider determines the number of organisms that will be removed from each population, simulating human hunting. Some limitations that could be improved upon include the process of reproduction. This process isn't very accurate because it doesn't require males and females, and the new organisms appear right away, and they completely resemble a full grown animal in their traits despite being a newborn. There are also many other environmental factors such as sunlight, space, disease, other populations, climate, and the actual environment including things such as escape routes are places to hide. These factors were not practical to include in a model because coding for each of them would've been more complicated than the platform can sustain, and the interface and code wouldn't be able to show all of those things without crashing. All of the variables would be too confusing for the model to be worth using. This model followed the life cycle of each organism and the code allowed for that to be consistent between all animals and all individuals. Once the model starts running, nothing needs to be changed, since all the sliders affect the model before pushing setup, making this a self-sustainable model. The sliders allow for factors changing just like they would in real life and allow you to experiment with independent and dependent variables for certain circumstances because not every ecosystem operates the same way. The four agents in the ecosystem go through transfers and fluctuations of their energy because certain energy amounts are required for an individual to undergo certain procedures, and other procedures take energy away from an organism, simulating how completion of certain activity changes the amount of energy an animal would have in real life.