When two questions are merged, answers from the source question are moved to the target question.
Question. Is the same true for the comments? Are the comments under the source question moved to the target question when two questions are merged.
Although I assume that if this is the case, typically the moderator handling the merger cleans up the comments which no longer make sense on the target question.
The FAQ post What is a “merged” question? (current revision) explains that: "All of the merged question's answers, including their votes and comments, become answers to the target question." However, it does not mention the comments under the question - only the comments under the answers.