You probably know the smell of freshly-mown grass. It is a very strong smell and, for some people, is relaxing. This smell comes from the cut grass and is made up of lots of chemicals that plants make. But, that soothing and very strong smell is actually a plant distress call!! Plants don’t have a nervous system, so they don’t feel pain. They need water, sunlight, nutrients, and their leaves and stems to survive. When any of these supplies is low, the plant has to conserve as much energy as it can and also sends out alarm signals to other plants. When grass is mowed, the grass sends out this smell to other nearby blades of grass to warn them about the danger. In this case, the danger is the lawnmower, which is cutting off it’s leaves and stem. The plants also increase their inner defense systems in case bugs or other organisms attack the plant. Soon, the smell disperses and the grass is able to regrow and thrive again. It is so cool to know that the grass you walk on is full of life and activity!