PRINCETON, N.J. (WPVI) -- A New Jersey university is using a "fleecy flock" to help keep their solar field trimmed and tidy.Princeton University is hosting a herd of sheep to eat the grass underneath and between their system of solar panels.The sheep have been grazing on the 27 acre field since March.University officials say the new method is a creative and economical way to keep grass and weeds in check."The sheep are actually quite docile, they're very gentle, but they maintain the grass and plants at a level that is really ideal"The solar field supplies clean energy to the university.The group of 75 sheep have been dining out at solar fields across New Jersey for years.