The four missing citizens are "missing" as depicted in the Carrot King Diner. The pictures contain the photographs of kids Shy Sky, Sleepy Bird, Magic Socks, and Crazy Comet. You can find the four missing citizens in the Carrot Cake Factory on 24 Carrot Island. Without obtaining the Drone Ears, you will not be able to enter the Rabbot launch room, and you will be sent diving down a hole into the Smelter Room which has a conveyor belt, which will pull you to the right, with strange metal posts, that go up and down and will crush you if they go down on you. Also, there is a hose squirting weird colorful liquid that could knock you under the metal posts. Eventually, you will find a pipe. Jump on it. If you jump off the pipe to the left, you will find the Drone Ears. Put them on. When you put them on, you will be able to enter the door to the Launch room.
All of Dr. Hare's minions in this mini-island wear pink versions of the Drone Ears.
In 24 Carrot Island, when the four missing citizens were controlled by the Drone Ears, they had rabbit teeth, swirly eyes and could only speak in simple sentences. However, in Dr. Hare's Secret Lab, the slaves seemed to be more conscientious of their actions. It is possible that the rabbot ears in Dr. Hare's Secret Lab are a different, more advanced model. This is also supported by the fact that the victims of the Drone Ears in 24 Carrot Island could be easily distracted.