Cell was designed to absorb androids 17 and 18, he couldn't absorb any other androids. He stabbed 16 in the neck with his tail to try an shut him down, but it didn't work since 16 was designed differently. And yes, 17 and 18 were built using human bases, 16 is a pure robot.Originally posted by Bittles
If I remember right, didn't Cell try to absorb number 16, but the needle thing on the end of the tail just poked him? Something about him being made from scratch whereas 17 and 18 used to be human. That's how I remember it anyways.