The halls are not deep under ground. If the weather is very cold, or very dry, the worms dig down deeper. Worms dislike cold or drought. They enjoy warmth. They also like water, and wet soil.
When winter comes the worms plug up the doors of their houses. This is done by dragging into the doorway a plant stem that will fit and fill it.
The worms carry into their homes leaves and stalks to eat. They bring out, and throw away, things which they do not like. Worms show much sense in the way in which they carry things in and out of their holes. If a stem will not go in, they turn it over, and try it in some other way.
Mr. Worm at Home.
Worms usually come out of their holes at night or in wet weather. If they go far from their house, they cannot find their way back. Then they make a new hole. Each worm lives alone.
Often in the evening or early morning, or during rain, you will see worms near their houses. You may find them with their heads just put out of their doors. You will see the worm casts in early day or after rain. It is then the worms dare to come out. Sun and heat dry worms up very fast, and so kill them.
Mr. Worm leaving Home.
The birds know all these ways of the worms. Watch a robin or a bluebird. He searches for his food at sunrise, or after sunset, or while it rains.