Voracious

One basic instinct among all living things is the instinct to get food and survive. Some creatures are more voracious than others. Creatures such as dinosaurs, sharks, or lions are more voracious than animals such as jellyfish. Voracious creatures are more aggressive and territorial when it comes to food. This is why dogs and wolves are so aggressive at feeding time because they have the "survival of the fittest" mindset. They know that they want to survive and in order to survive, they must have food. They will do whatever it takes to get food and survive.