The Hungarians have had it with the invaders known in the media as “migrants” and are doing something about it: Hungary has begun building a fence on the country’s southern border with Serbia, meant to stem the unprecedented flow of migrants, the government said Monday. Military personnel began working on a 150-meter (490-foot) “sample section” Monday morning on the outskirts of the town of Morahalom, where a bulldozer and other heavy machinery were preparing the ground for construction, according to a joint statement from the interior and defense ministries. “A daily average of 1,000 illegal border crossers are arriving in...