Quote from : A Hat Full of Sky Book

Tiffany jumped when she saw a balloon sail up above the trees, catch the wind, and swoop away, but it turned out to be just a balloon and not a lump of excess Brian. She could tell this because it was followed by a long scream of rage mixed with a roar of complaint: “AAaargwannawannaaaagongongonaargggaaaaBLOON!” which is the traditional sound of a very small child learning that with balloons, as with life itself, it is important to know when not to let go of the string. The whole point of balloons is to teach small children this.