Millions of us use messaging apps to communicate with each other, gossiping, joking, and wooing our way to friendship. Trees also talk to each other, but while we have the World Wide Web, they have the Wood Wide Web—a fungal network (mycorrhizal network) that grows around and inside their roots, connecting them to each other. When a tree is being attacked by predators, it can release chemical signals through the network, which warns neighbours to raise their defences. They also send distress signals during drought and spells of disease, which prompts other trees to change their behaviour. In addition to communicating with each other, trees use the network to share food, and trees such as the black walnut even use it to poison their rivals
