My yard is primarily pine trees. I've been told that when the sap rises in the trees, it produces the noise that people often think is made by cicadas. Can moving sap really cause the forest hum?
Sap in Pine Trees
Certified GKH Gardening Expert
Well, this is a new one on me. The sap flowing through pine trees does not make that sound, but the cicada noise would indeed be coming from the trees. Cicadas actually favor pine trees for feeding and will often chant their 'mating' calls from the trees as well. This is why you hear them so good around pine trees, though they do get loud enough to hear them just about anywhere.