Like most amphipods, C. volutator feeds on plankton. On high tide, it produces a current with its slightly elongated hind legs, to make the water flow through its tube. On low tide, it scratches along the surface with its elongated second pair of antennae, producing star-like patterns.
The silk-lined U-shaped tubes reach about 3 cm deep in summer, and up to 12 cm in winter, to escape the freezing point. The tubes have a diameter of about 2 mm. When travelling, C. volutator produces patterns similar to a zipper.
The species lives up to a year, and produces up to three generations during its lifetime. The females breed the eggs inside their pouch. They are resistant to significant fluctuations in salinity.
They can occur in huge quantities: up to 40,000 per m² have been observed. This makes them an important part of the food chain.