Mel Gibson is going back to school, and the co-eds are cooing. Mighty Mel, 45, is set to play a farmer for filmmaker M. Night Shyamalan (“The Sixth Sense”). Their movie, “Signs,” is due to begin filming in September outside Philadelphia, reports the Associated Press. After a lengthy location shoot to find appropriate farmland, producers have settled upon Doylestown’s Delaware Valley College, a private four-year agricultural school. “Everyone knows he’s coming,” said student Mitzi Weikel, referring to Gibson, “and all the girls are waiting.” Filming is expected to last through the end of this year on the school’s 100 acres of cornfields. In keeping with the Shyamalan field of interest, the movie involves the paranormal: Gibson’s character discovers large circles and other patterns on his land. (Generally, these “crop circles” are interpreted as signs from outer space aliens.) “Our biggest concern is that when they leave, they leave the fields the way they found them,” said college president Dr. Thomas Leamer. “That’s part of the agreement.”