Five actors in this episode about aliens have appeared in the "Star Trek" franchise. Walter Koenig (Ensign Pavel Chekov), George Takei (Lt. Hikaru Sulu), Grace Lee Whitney (Yeoman Janice Rand), Majel Barrett (Nurse Christine Chapel) were all regulars on the original Star Trek (1966) and Wil Wheaton (Ensign Wesley Crusher) was a regular on Star Trek: The Next Generation (1987). Meanwhile, Bill Mumy was a regular on Lost in Space (1965) as well as Babylon 5 (1993).
At the time this episode was filmed, it was likely Bill Mumy had already worked on an episode of Star Trek: Deep Space Nine (1993).