Treehoppers (a type of insect) produce honeydew, which ants use for food. Treehoppers have a major predator, the jumping Spider. Researchers hypothesized that the ants would protect the treehoppers from the spiders. During a one-year study, researchers found no difference in treehopper population in any of their control and experimental groups. What could they measure during the second year to gain information about why this might have occurred