"A scarlet steam engine was waiting next to a platform packed with people. A sign overhead said Hogwarts Express, eleven o'clock. Harry looked behind him and saw a wrought-iron archway where the barrier had been, with the words Platform Nine and Three-Quarters on it. He had done it.
"Smoke from the engine drifted over the heads of the chattering crowd, while cats of every color wound here and there between their legs. Owls hooted to one another in a disgruntled sort of way over the babble and the scraping of the heavy trunks."
- J. K. Rowling, Harry Potter and the Sorcerer's Stone
Okay, so what I want to know is, where are all the cats? Toads are out of fashion, owls live in the owlery, but the only cats we ever see, besides here, are Crookshanks and Mrs. Norris. (Well, and Professor McGonagall.) Where are these students keeping their cats of every color? Did they all belong to 7th-years? Did Hagrid make a decree? Alas, I am betting that these burning questions will not be among those finally answered in book 7.