Thousands of live bees were used during production, with the understanding that the bees would not sting without a queen present. However, this theory proved incorrect, and Vanessa Morley, who played the Samantha Mulder clones, was stung during filming. She kept quiet and did not react until the scene had finished filming, leading Spotnitz to call her "a trooper". The cold open for the episode, with multiple cloned boys, was achieved with motion control photography, allowing for two children to play all five of the clones; multiple takes were recorded with the boys in different positions, and with the camera controlled by a computer to follow exactly the same motions for each take, these could be seamlessly composited together.