Why can the humans in the Stuart Little films understand mice and birds talking, but not cats?

I’ve rewatched the two live action Stuart Little movies recently. I enjoyed them a lot growing up (I always liked 2 a bit more). I feel this was something I noted then too, but the Littles have conversations with Stuart, a mouse, and Margalo, a bird. They can understand them. Yet this same logic doesn’t apply to Snowbell, their cat? He makes little remarks in their presence but they never acknowledge it. Is it that for some reason humans do not hear them talk? Or are they potentially just sick of Snowbell’s shot and pretend not to hear him or something?The world of Stuart Little was already a bit weird, like how you cars and planes can be physically piloted by a tiny occupant without the need for a controller or how there’s tiny copies of books written specifically for an animal like a mouse, but the cats talking point always stuck out to me. via /r/movies https://ift.tt/2AGacd1