 Why does Doctor George think he can substitute Mrs. Glubbes nuetroid without her noticing?
When a pet neutroid died, a family was broken with grief; but most couples could endure the death of a cat-Q or a dog-F. Class-C couples were allowed two lesser units or one neutroid. This could be a ruse to bring a stop to investigations when one animal is found. If allowed to reach age-set or adulthood, such a deviant could be dangerous to its owner or to others. Its replacement-quota of new neutroids was around three hundred animals a month. Of course, no hospital would play along with her fantasy and take a neutroid, especially since she couldn't pay for its treatment." You're welcome to it, Doctor, but you can't fake a serial number.
 Neutroids from the same series look identical.
 Neutroids can only say a few words. It won't be able to give itself away by saying the wrong thing.  Mrs. Glubbes believes the neutroid is a human baby. She's probably crazy enough not to notice a difference.  He plans on changing the serial number.  Neutroids from the same series look identical.