[2][3] Like many similar thalassinidean decapods, C. subterranea is a deposit-feeder that ingests sediment particles in order to scrape off and digest the organic coating called biofilm that sticks to them.

[2] As its scientific name implies, this species has a burrowing habit and lives underneath the wet, sandy sediment of its benthic zone habitat.

C. subterranea creates complex, multi-branched tunnel systems up to 81 cm deep from the lower shore to the shallow sublittoral.

Each tunnel complex has several inhalant shafts which terminate on the surface with a funnel-shaped opening in the center of a conical mound of ejected sediment.

[7] The construction of the burrows varies according to the characteristics of the sediment in which the individuals dwell and reach their maximum depth and complexity in Scottish sea lochs and other areas with fine-grained mud.