Peggy Peterson, age 11, Sioux C y, Iowa, for her question:

Why do mother guppies eat their young?

Mrs. Guppy is a slender, silver colored fish not much longer than an inch. She is one of those darling little tropical fish. The graceful creature, however, has a very bad name. She has been known to eat her own children.

We cannot condemn her too much for this because it is an accident. Mrs. Guppy gives birth to live babies. They are very tiny little creatures that swim off into the water as soon as they are born. Mrs. Guppy is not a smart animal, in fact she is quite stupid. She does not even know that the little creatures are her own babies. She sees them frisking in the water, mistakes them for food and gobbles them up.

If you keep pet guppies, there is a way to save the young. Place two sheets of glass in the water, arranged in a V‑shaped trough. Leave a slim crack between them. When the babies are born they will slide down through the crack in the trough. Mama cannot reach them there, safe in the water below the trough.