In an ecosystem, producers are organisms (usually plants) that produce their own food through photosynthesis. Primary consumers are herbivores that feed directly on producers. Secondary consumers are carnivores or omnivores that feed on primary consumers. Tertiary consumers feed on secondary consumers, and so on. A Crabapple tree is a producer (plant). A Caterpillar is typically a herbivorous larva that feeds on leaves (producers), making it a primary consumer. A Frog is a carnivore (e.g., eating insects), making it a secondary or tertiary consumer. A Sparrowhawk is a bird of prey that feeds on other animals (e.g., birds, small mammals), making it a secondary or tertiary consumer.