The name of an animated movie?

Its old, and its animated. Its about animals, and i think its a mole,
and they gas its parents. And at the end a person wearing a big suit
thing and gas mask pick it up, but then let it go.

Theres another one and im not sure if its the same movie as the one
above, but the cover of it has mice in a hot air balloon. I think it
has something to do with the uncle taking care of the kids? Im not
sure

If you know what these movies are called, i will be forever in your
debt :)