Rats are a danger to species unique to the Galapagos Islands.
Officials say they devour the eggs in particular, and threaten things like falcons, finches, tortoises, lizards and iguanas.
"This is one of the worst problems of the Galapagos Islands. Rats reproduce every three months and eat everything," says Juan Carlos Gonzalez, an expert in conservation.
Both islands affected by this phase, Plaza Sur and Pinzon, are uninhabited. They are so infested that they have 10 rats per square metre.
The rodenticide specially developed in the United States, is packaged in small cubes that attract rats, but repel other species. These cubes disintegrate in a week.
The 34 Galapagos hawks that inhabit the island of Pinzon were taken away to prevent them from eating any poisoned rats. They will be released in January. On the other island, 40 iguanas were also taken to a safe place.
The extreme isolation of the Galapagos Islands led to the development of unusual animal life, especially turtles. These species inspired Charles Darwin, who visited the islands in 1835, and his theory of evolution by natural selection.
The Canadian Press