It excavates and occupies a burrow in soft sediment from which it emerges, mainly at night, to feed on fish and invertebrate prey.

[2][3] Squilla empusa is reported from the eastern seaboard of the United States with a range extending from Cape Cod to the Gulf of Mexico.

[2] The summer burrow of Squilla empusa consists of a tube with typically two openings connected by a horizontal tunnel some 15 to 50 cm (6 to 20 in) below the surface of the sediment.

This behavioural adaptation may enable Squilla empusa to inhabit locations where the water temperature falls too low in winter for it otherwise to survive.

A vigorous fanning action of the pleopods causes particles of sediment to become suspended and the current produced pushes the plume backwards past the telson.

The raptorial claws are unfolded with great rapidity to spear, slash and immobilise the prey, which is brought back inside the burrow when caught.