Concept:The poem is about a blood-sucking insect that shares the speaker’s bed and attacks at night.Explanation:The speaker calls the creature a “parasite” that lives in the little bed and sucks blood from his head.It breeds in the bed and becomes active only when the speaker is fast asleep.It seems to vanish before twilight, which is typical of bedbugs that hide during the day.These details point clearly to a raid of bugs rather than a dream or mosquitoes.Answer:C. raid of bugs