At least 500,000 Liberians are affected by a plague of caterpillars that is destroying crops, polluting drinking water and spreading to neighboring Guinea.
At least 100 villages are affected in Liberia's richest agricultural region near the borders with Guinea and Sierra Leone.
The black, hairy caterpillars - also know as "army worms" - are overrunning homes and polluting wells and streams with feces.
"The caterpillars are enormous. They are uncontrollable," says resident Sando Kollie, who fled the infestation with his family. He says the caterpillars drove his children and their teachers from their classroom.
"The caterpillars took over the schools in the community. There is no way for the children to go to school. All the community is surrounded by caterpillars. And even the water, the well we go to drink to draw our drinking water, the caterpillars have taken over the well. The whole place is surrounded by caterpillars," says Kollie.
The caterpillars began breeding high in the canopies of forest trees where hand-sprayed pesticides could not reach. They have descended to devour crops including banana, plantain, cocoa, and coffee.
"My little crops that I have at the back of the yard, everything has been eaten up," says farmer Joe Morris.
Morris says he lost not only the small crops in his own yard he used to feed his family, but everything he planted in the field as well.
"All the caterpillars have eaten all of my crops on the farm. And now we are displaced. Right now where we are living, no food to eat, no one to help us," he said.
Like many of those displaced by the infestation, Morris and his family are living in a school building farther south. Liberian President Ellen Johnson-Sirleaf has declared a national emergency and says water and food are being supplied to those displaced.
The swarms are spreading quickly as one female can lay as many as 1,000 eggs a week. Many of the army worms have now dug protective cocoons underground, beyond the reach of pesticides.
United Nations Food and Agriculture entomologist Winfred Hammond told VOA that they will re-emerge in about ten days as adult moths capable of traveling long distances at night.
"They move in different directions depending on the wind direction and also on the speed of wind. They could go as far as a thousand kilometers from the spot where they were breeding," says Hammond.
The caterpillars have already moved more than 25 kilometers into Guinea, eating crops and displacing farmers in several villages. Sierra Leone has pre-positioned pesticides in areas along the Liberian border. A public education campaign of posters and radio broadcasts is urging civilians to notify authorities at the first sighting of the caterpillars, which can grow as long as five centimeters.