Mrs. Frisby discovers the rats have a literate and mechanized society. They have technology such as elevators, have tapped the electricity grid to provide lighting and heating, and have acquired other human skills, such as storing food for the winter. Their leader, Nicodemus, tells Mrs. Frisby of the rats' capture by scientists working for a laboratory located at the National Institute of Mental Health (NIMH) and the subsequent experiments that the humans performed on the rats, which increased the rats' intelligence to the point of being able to read, write, and operate complicated machines, as well as enhancing their longevity and strength. This increased intelligence and strength allowed them to escape from the NIMH laboratories and migrate to their present location. Jonathan Frisby and Mr. Ages were the only two survivors of a group of eight mice who had been part of the experiments at NIMH, and made the rats' escape possible. Out of respect for Jonathan, the rats agree to move