Hello, I'm an expert in the field of biology with a focus on entomology and soil ecology. I'd be happy to explain why worms come out of the ground when it's raining.

Worms are creatures that thrive in the soil, where they play a vital role in aerating and fertilizing it. They breathe through their skin, which they do by taking in oxygen from the air that is in the soil. When it rains, the water can saturate the soil, pushing out the air and reducing the amount of oxygen available to the worms. As the soil becomes more waterlogged, the worms' burrows can also fill up with water, making it difficult for them to move around and find the oxygen they need.

To avoid drowning and to find more oxygen, worms will often come to the surface when the soil is too wet. This behavior is also influenced by the fact that the rain can make the ground surface more conductive of oxygen. Additionally, worms are sensitive to changes in soil pressure and moisture, and they may emerge in response to these changes.

It's important to note that not all worms will come to the surface during rain, and the behavior can vary depending on the species and the specific conditions of the soil and rain.

read more >>

In fact, they come to the surface during rains (especially in the spring) so they can move overland. The temporarily wet conditions give worms a chance to move safely to new places. Since worms breathe through their skin, the skin must stay wet in order for the oxygen to pass through it.read more >>