The phrase "to feed on" means to obtain nourishment or energy from something. It can refer to consuming food, but it also has other meanings such as using information or resources for growth and development. For example, a person might say that they are feeding their mind by reading books or studying, meaning that they are taking in new knowledge and ideas to help them grow intellectually. In nature, animals often "feed on" certain plants or prey to survive, while parasites may "feed on" the host's blood or tissues for nourishment.