How does it move?

Gilbert Haven Trafton, Biology of Home and Communauty. A Textbook for high Schools, New York, The MacMillan, 1923, p.35.

VI Case-building caddis worm.
1. How does it move ?
2. Does it ever come to the surface of the water ?
3. Of what materials is the case made ?
4. Carefully tear a case to pieces without injuring the insect. With what is the case lined ?
5. Describe the worm.
6. Put small bits of grass and pebbles in the jar. Keep the worm for several days to see whether it will build a new case.