I've certainly seem programmes about the same idea - either physically or intellectually Neanderthals had bigger brains than Homo Sapiens. I can't remember the exact cause of their extinction, however, I recall something to do with their failure to migrate, or mis-migration as it were
On topic though, I think an expansionist pack of animals would perhaps be justified in the slaughter and conquest of human suburbs. However I would certainly see it as cruel and unaccetable. While I do care/sympathise with animals, I in no way think they have anywhere near the same right to life as humans. I was a bit astounded with the strong views many members expressed in the thread about cats abused - some that the abusing humans should be jailed for it etc. While there should be punishments for those that purposefully mistreat animals, they should not be to the same degree of things such as child abuse.
Humanity reached the top of the food chain, and arguably abused its power - and is continuing to do so in seemingly less barbaric ways. Thats how it goes. I don't like the fact that as a species we've killed of those we didn't like (human and non-human) - that doesn't mean I'd sit back uncaring when a group of angry squirrels decide to molest a few human housing estates.