what are food webs?
Check these sites.
http://www.sciencebob.com/lab/q-web-chain.html
http://images.google.com/imgres?imgurl=http://www.bigelow.org/edhab/images/food_web.jpg&imgrefurl=http://www.bigelow.org/edhab/fitting_algae.html&h=300&w=314&sz=45&tbnid=Lt9KCdxPFLKtKM:&tbnh=112&tbnw=117&prev=/images%3Fq%3Dfood%2Bweb%26um%3D1&start=2&sa=X&oi=images&ct=image&cd=2