THIAROYE-SUR-MER, Senegal — The fishing village has long sent its men to sea, but after foreign trawlers scraped the bottom clean, the men began coming back empty-handed. It has long sent its men abroad for work, too, but their luck is often no better.

Last November, when El Hadji Macoura Diop, a 37-year-old fisherman, failed to reach Europe by boat, he could not bring himself to call his wife and tell her he was giving up. “I knew it would just destroy her,” he said.

Hard as it is to leave home for an unknown land and an uncertain future, coming back, migrants say, can be even harder. Often, they feel ashamed to admit defeat, especially to families that may have scrimped to raise money for their trip. And they struggle to reintegrate into the societies they left behind.

In 2010, when he was 19, Yaya Guindo fled his life herding cattle in a small farming village in Ivory Coast. Last winter, after eight years on the road working in construction and at restaurants, he returned, broken and defeated, from a detention center in Libya.