Week of July 9, 2023 – July 15, 2023

Sunny Guyette Staff Member and Environmental Educator

by Sunny Guyette, Environmental Educator

We have been getting quite a bit of rain recently and a recurring question I’ve had is ‘why are there so many worms on the surface when or after it rains?’. Ever since I was young I would see about fifty worms crawling on the sidewalk after a rainy day, but I never really thought to investigate my lasting question. So, I finally decided to do some research. I came to the conclusion that there could be many different reasons as to why worms come to the surface after a nice rain.

Researchers have not been able to determine what the exact answer is, but one common answer that I came across is that the vibrations from the rain hitting the surface could feel like the same vibrations of when a mole, one of the worm’s predators, is tunneling through the soil to find food. In this case, worms will go to the surface for safety.  Another possibility is that the soil may flood with water and therefore flood the worm burrows. The worms are no longer able to get oxygen, so they come to the surface to breathe.

Worms are vital creatures for our ecosystems, so it is important to learn about them and their behaviors! On the next rainy day, go outside and look for worms. Try to make your own observations on why there are so many worms on the surface. Are they on a slab of concrete or pavement, grass, or the forest floor? Which direction are they heading towards? Try to imagine being a worm, what would you do if you thought a predator was coming or your home was flooding?

Want to learn more about this topic? Check out this article from the Nature Conservancy.