Animals store glucose in the cells and muscles and excess glucose is stored in the liver as glycogen.
Human chorionic gonadotropin (hCG) is secrete by the embryo early in pregnancy to keep the corpus luteum for dying. This positive feedback will maintain the corpus luteum, which secretes Progesterone and Estrogens throughout pregnancy, in order to keep the endometrium well to nourish the embryo/fetus.
You could do regular daisies, or pet grass... It could be almost anything.
I hope this helps!<span />