Book recommendation: "Entangled Life" by Merlin Sheldrake [0].
The author discusses the possibility of intricately connected subterranean mycelium networks electrically signaling each other acting as a giant nervous system. He stops himself from calling it a giant brain, but admits that the possibility isn't really far fetched given everything else that we know about fungi.
It's a fantastic book. Strong recommend.
[0]. https://www.amazon.com/dp/B07WJ84V9B/ref=dp-kindle-redirect?...