. The Moth and the Flower The hawk moth and the datura plant have what scientists call a "mutual" relationship. one that benefits both species. These types of relationships in nature have long fascinated scientists, in part because this kind of cooperation seems so complex and weirdly human. One partner in this type of relationship often seems to benefit more, which makes scientists especially curious. Each large, trumpet-shaped datura flower blooms only for one night. The flowers begin to open at twilight, and their strong lemony scent draws the hawk moths. The hawk moth is as big as a man's hand. It drinks nectar from the flower and, while on it, transfers the pollen that enables the flower to create seeds. The female hawk moth deposits her eggs on the gray-green datura leaves. The caterpillars hatch and eat the leaves down to nubs. The plant pays a high price for having its pollen moved! Scientists did an experiment to study what effect the moths' behavior has on the root system of the datura plants. In each pair of test plants, the first plant was protected from hawk moth caterpillar