We have been seeing spittle bubbling out of trees, especially in today's rain. Might be a spittlebug.
"a fat little dark-eyed green creature about the size of a sesame seed
called a froghopper nymph, so named for the adult insect's squat shape,
pop eyes and leaping ability. The nymph stage is better known as a
spittlebug. Froghoppers/spittlebugs insert their "beak" & suck
sap through their bodies, extracting nutrients. As the liquid comes out
the other end, mixed with soapy abdominal secretions, the insect puffs
air into it through a special organ, blowing bubbles. The froth flows
down and around the nymph (they feed facing head down), keeping it cool,
moist and hidden from you (unless you look)."