True to their name, yellow larvae build a foamy layer of protection over themselves while they grow and develop. This froth is a mixture of mucous and their own liquid waste that is whipped by small protrusion at the tip of the abdomen. The result is a blob of white, bubbly 'spit' on the branch or tree. Young Two-Lined Spittlebugs hide in this foam to avoid predators, but also to keep their bodies moist. After they mature, adults no longer need the bubble nest and have hard exoskeletons that resist drying out. Adults can secrete a yellow fluid from their feet as they jump away. This is believed to distract or deter a predator. Two-Lined Spittlebugs are most active during the warm summer and autumn months.