Plants are portrayed as passive lifeforms, which simply grow, wither or get eaten, or in the case of heliotropes, turn towards the light. But this is a false view; actually, plants actively react to their environment, they communicate with each other, and they fight predators chemically. Plants have something which we may call intelligence.
Here is how it works: If one of the network plants is attacked by caterpillars, the other members of the network are warned via an internal signal to upgrade their chemical and mechanical resistance—making their leaves hard to chew on and less desirable. This system works to spread the information amongst the plants and to ward off caterpillars.
“This is an early warning system, very much like in military defense, but then more effective: each member of the network can receive the external signal of impending herbivore danger and transmit it to the other members of the network,” Stuefer said. The attacked leaf is lost. However, the remaining leaves are protected against predators.