At least four female Williams Hall students received obscene or nuisance phone calls Monday morning, said MSU police Sgt. Florene McGlothian-Taylor. The students reported that each girl on the floor received such a phone call between 8 a.m. and 9 a.m. At 8:25 a.m., the male called one resident and referred to her by her nickname. He pretended to be her boyfriend and made obscene references. Another resident was asked to describe herself when the male called at about 8:30 a.m. Other calls were not obscene and made no threats. Police have no suspects.