Every year in Cuba, millions of crabs emerge from the forest at the beginning of the spring rains and head for the waters of the Bay of Pigs, crossing streets and highways on a perilous journey to mate and reproduce.

Now underway, the migration causes concern to drivers who try to swerve in an often futile attempt not to kill the crustaceans. The crabs are a nuisance to residents but the sight of their road-crossing is a wonder for tourists and other first-time onlookers.

“They got here before us,” said Amaury Urra, a 50-year-old hiking guide who spent his entire life in this part of the Ciénega de Zapata, the largest wetland in the Caribbean, particularly picturesque for the backdrop of turquoise sea waters and the coastal cliffs. ″We’re used to this.″

“Where I live, which is in the center of the town of Girón, the crabs don’t get there as much,″ though there are plenty on the outskirts, he said.