Why come out in rain?

Worm come out in the rain because wet conditions make it easier and safer for them to move and breathe.

Worm breathe through their skin, which must stay moist to absorb oxygen. When the ground is dry, worm risk drying out if they come to the surface. Rain keeps the soil and surface wet, allowing worm to breathe comfortably while moving around.

Rain also floods worm tunnels underground. When soil fills with water, there is less oxygen available below the surface, so worm move upward to avoid suffocating. The surface becomes a temporary safe place where oxygen is easier to get.

In addition, wet ground reduces friction, making it easier for worm to travel across the surface. This helps worm move to new areas, find food, or escape crowded soil. Once the ground dries out again, worm usually return underground to stay protected.