Somnus is said to have lived in “a cave from which all light was excluded, and to which all sounds and noises of the world penetrated either not at all or dully muffled.” The rooster never called there to Aurora, nor was there a watchdog or goose to disturb the silence. No wild beast, nor cattle, nor branches rustled with the wind, nor sound of human conversation or clamor of tongues broke the stillness.

There was only the gently flowing river Lethe, the river of forgetfulness, and by its murmur enticed those who heard it to sleep. Poppies grew by the door of the cave, from whose juices Night distilled slumbers that she scattered over the darkened earth. There was no gate to creak on its hinges, nor any watchman to call out.

Somnus lay asleep on a couch of black ebony adorned with black downy-soft plumes and black curtains. Around him lay dreams, some even sat on his head; resembling various forms, as many as the harvest produces stalks of grain, or the forest leaves, or the seashore grains of sand.

Whenever anyone was able to see Somnus, he was holding a poppy of forgetfulness or a horn from which trickled the drops of slumber. His twin brother was Mors (Greek: Thanatos) or Death, often represented as a quiet, pensive youth with wings, who stood beside a funeral urn decorated with a funeral wreath. Sometimes he held an extinguished torch in his hand.

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