Answer:
The literary device used is a metaphor.
Step-by-step explanation:
A metaphor is a literary device that is used for comparison. This means that when a comparison is made between two unrelated things and their meanings cannot be taken literally, it is a metaphor.
In the given dialogue of Dr. House, a metaphor is used when the comparison is made between them (House and Wilson) and birds. House compares them to "an early bird . . .and a night owl." This comparison is used in the metaphorical sense.
Thus, the correct answer is a metaphor.