He nice to spiders --they eat up the flies and keep the zoo animals happy. Miserable lions swatting at flies: spider Helen spins a web--contented lions with pleased grins lolling in their cages. Ditto for elephant, zebra, camel. An ill-informed clean-up halts the euphoria, but all ends well with Helen getting the recognition she deserves (and spawning a large supply of fly-fanciers). Cheery sketches of a web a-spinning, animals a-swatting, keepers a-puzzling--all in Mrs. Graham's familiar-from- Harry style--enliven the informative fun.