Jim Tomaso, age 11, of Philadelphia, Pennsylvania, for his question:

Is the weasel really related to the ermine?

Experts class the ermine as a slightly larger weasel, called a stoat. The smaller weasel always wears a reddish brown coat with snowy white underparts. Weasels, with slight variations, are at home in Europe and North America, also in northern regions of Asia and Africa. Their slim, low slung bodies range from seven to about 20 inches in length.

The stoat weasel, alias the ermine, is a native of northern regions where snows always cover the ground in winter. In summer, his short silken fur is reddish brown with creamy colored underparts    and there is a black tip to his pretty little tail. Come fall, he molts his summer fur and the winter coat that grows in is ermine white   with the tail still tipped in black. The summer stoat is dressed to match the summer scenery. When he changes his coat to match the snow, he is called an ermine.