Studies have shown when rats get too crowded, even with enough food, they begin to kill each other. Do humans do the same. I went to New York City one time back in 1991 or 92. My daughter was in the local high school band and they were chosen to play in the Macy's Thanksgiving parade. We went there in 10 chartered buses. 7 with the bandmember kids, and 3 with parents or relatives. There was a flower shop on every corner in Manhattan. It dawned on us they had no trees, grass, or flowers except in Central Park. High rise apartments everywhere and businesses all on the streets. I would not want to live there. Too crowded, no yards. No fresh air. We actually had to stay in New Jersey across the river because there was no place to park the buses. Hotel had grits, but no biscuits, only toast, bagels, and crossonts. Only had bacon, no sausage either for breakfast, and only scrambled eggs as well as fruit and cereal.
Along the trip we stopped in Pennsylvania. Nice people there. New Jersey folks were rude. New York wasn't too bad. Did go to the top of the World Trade Center. People were like moving dots and cars were like ants from that height.