I found several of these on my hike at Ginny Springs. What is it?
This is the home of a young Spittlebug, also known as a Froghopper. While in the nymph stage, these insects produce a thick liquid and wiggle their bodies to churn it into a froth. Inside that mass of bubbles is a tiny, green insect. The froth hides them from predators, acts as insulation to protect them from heat and cold, and also keeps them from drying out. While hiding inside the froth, the young Spittlebug gets food by drinking the sap from the plant.