The phrase “the smell of death” probably brings the idea of decaying fish, mammals, or even people to mind. If you’ve had the unfortunate experience of smelling decaying flesh, then you know how strong and awful the odor is. Many describe it as a smell that literally stays with you for the rest of your life.

But not everything that dies emits a terrible smell. In fact, there is one type of death that actually smells very good and reminds everyone of summer.

It is the smell of grass being taken in the middle of its prime!

Most of you have smelled fresh-cut lawns in the middle of summer and probably enjoyed the scent. Not only is it a nice aroma, but it tends to bring to mind pleasant memories of our carefree childhoods and summer vacations. That smell comes to us thanks to an organic compound known as a green leaf volatile (GLV). GLVs are part of the natural defense systems of plants. Since plants can’t fight or get up and run, they have evolved to handle threats quite a bit differently than animals. GLVs act differently in various plants and are often contingent upon the threat. For instance, when caterpillars eat coyote tobacco leaves they attract an insect that eats them!

Fortunately for us, no Mothra-sized creatures will come to our lawn’s rescue when we cut it. Nonetheless, the smell the grass emits is a defense mechanism. But if it is a defense mechanism, why doesn’t it actually seem act as a repellent, at least when it comes to humans?

It turns out that the GLVs grass emits when we cut it aren’t the only GLVs that humans think smell good. Most fresh fruits and vegetables we eat also emit GLVs when they reach the end of their life cycles, which suggests that, just as plants have evolved by using GLVs for defensive purposes, humans have evolved to know when something is ripe and edible.

So, the next time you’re taking a stroll through your local supermarket’s produce aisle and enjoy the smell, just remember that it’s the smell of death.