Out of the darkness appeared a snout.

“Fei zhu! Fat pig!” 8-year-old Shino Chen shouted to her younger brother as she jumped up and down and pointed at a wild boar.

The hairy black pig, which must have weighed at least 150 pounds, grunted and snuffled through a flimsy, old fence along the sidewalk. The children tiptoed toward the animal then sprinted back to their father’s side.

Kenneth Chen, 44, and his children visit the boars almost every night. All they have to do is step out of their apartment here in the neighborhood of Tai Wai, located on the fringes of an ever-expanding metropolis.

“I bring my…