Food relationships provide the energetic basis for life. They also determine which species live together. We can rarely directly observe what food an animal eats. Usually, we have to rely on analyzing feces, pellets, and pluckings. Instructions are provided on analyzing these samples for hairs, plant remains, or pollen taken from flower visitors. Artificial food sources can be used to study animals, such as ants and flower visitors, e.g., bumblebees. Many fruit-producing plants are dependent on animals for their propagation. Large animals play a unique role in trees and palms. Analyzing the prey spectrum of carnivorous arthropods also requires laboratory work.