We have a natural tendency to think of trees as, although clearly living, largely inanimate. After all, they neither move nor make sounds, except due to the wind blowing through their branches. Trees are lovely,and useful, but they're just there.
Yet in the last couple of decades, science has been piecing together a different story. Trees whose leaves are attacked by insects produce a chemical to make their leaves taste bad and ward off the attack; that doesn't seem surprising. But the trees also release a chemical into the air, in response to which the neighboring trees also produce the chemical to make their leaves unpleasant for the insects; they prepare for the attack before the insects reach them. The first tree attacked has warned its neighbors of the coming assault. That seems very surprising.
