This document discusses food chains and webs. It explains that producers, like plants, are the beginning of the food chain and get their energy from photosynthesis. There are different levels of consumers that eat producers or each other, including primary consumers like squirrels, secondary consumers like cats, and tertiary consumers like wolves. Omnivores can be primary or secondary consumers. Scavengers and decomposers, like bacteria and fungi, break down dead organisms and return nutrients to the soil to complete the cycle. A food web is a more accurate representation than a food chain because organisms have multiple relationships in an ecosystem.