Hormones play a crucial role both in plants and animals. As we all known, hormones work through specific receptors in different organisms. Therefore, the hormone interaction between plant and animal is an interesting question worth discussing. Recently, food safety has become a common topic concerned by consumers. A widely discussed rumor such as “Fruit bulking agent is some human reproductive hormones” leads us to consider whether animal hormones did regulate plant growth. Based on the large amount of previous research, we demonstrated that animal hormones did affect plant, such as steroid hormones for livestock feed could regulate physiological processes in plant including flowering, senescence and stress resistance after excreted into the environment. Here, we summarize the previous studies and systematically discuss the effects of animal hormones on plant growth and development.