Ants tend to treehopper nymphs for honeydew

These white treehopper nymphs, filmed in the Amazon rainforest of Ecuador, feed upon sugar containing sap of a plant. Excess sap is excreted as honeydew through an extensible tube (see video at 0:55) that prevents contact with the treehopper nymph, as otherwise it would promote fungal growth. The honeydew is collected by the ants that feed upon the sugar and, in return, protect the treehoppers from predators. This is an example of mutualism, a form of symbiosis where both species benefit.