Answer:
The literary device used is a metaphor.
Step-by-step explanation:
A metaphor is when a comparison is made by using things unrelated. This figurative speech uses descriptive words to talk about things by equating two things that are not necessarily related or connected.
In the given speech/ dialogue by Dr. House, he uses a metaphor to make comparisons when he talked about "[himself as] a night owl" while also adding that "[Wilson] is an early bird."
Additionally, he extends the metaphor when he talked of keeping Wilson in "his own cage". This compares Wilson to a bird kept in a cage.
Thus, the literary device used is a metaphor.