!! FridgeBrilliance:
* It seems rather odd that the Queen of England would have fake jewels while a random surburban family has real jewels, but then again, we're never shown where the ruby Rita's after came from. It's entirely possible that it was just any old fake jewel from say, a craft kit.
** To add to that, who says the jewellery Rita receives at the end are real? Roddy taps the ruby on its side, where there is incidentally metal. As said, it's odd for a surburban family, even a rich one, to possess so many real rubies and emeralds and pearls...
** Given that it is stated, repeatedly, that Roddy's home is in the Royal Borough of Kensington where a terrace house can easily exceed £20,000,000.00, it's not unusual for a family in such an area to own real jewels.
** Also, we're taking Toad's word that he was a pet of the royal family.
* Roddy's owner leaves an entire box of food in his cage, so she's not going to be surprised that the rat living in the cage is now much fatter. In fact, one might notice Sid looks ''exactly'' like Roddy, except the extra weight.
* The loneliness Roddy feels because he is a pet with no family definitely is understandable to begin with, but there is an extra layer of significance considering the sort of animal he is. It's a well-known fact among fancy rat owners in RealLife that they are social animals and must be kept in pairs (at least) so they won't become depressed. Roddy's owner was irresponsible in not giving him a cagemate.
** Likewise, this must also be why Sid didn't consider flushing Roddy down the second time (as an act of villainy).