Have students observe, sketch, and try to identify and categorize the different organisms in your greenhouse. Which pests seem to have which plant preferences? What types of environmental conditions seem to attract different organisms? Invite students to research and investigate the life cycles and needs of common greenhouse pests and beneficial insects, then have them use this information to invent ways to reduce pest numbers. Find out how commercial growers deal with pest problems. Research and debate the use of chemical versus biological approaches.