Authorities in Liberia have set up a command post and called on international experts to help fight an invasion by millions of crop-devouring caterpillars that are eating their way across the country with dire economic consequences. The inch-long (2-3 centimeters) caterpillars are clogging wells and waterways with excrement and devouring vital crops including banana, plantain, coffee and cocoa. They swarmed around a clinic in one town, preventing people from accessing it, the Ministry of Agriculture said. "The pests were found to attack practically all crops of economic value. Their droppings pollute the waters, rendering them unwholesome for human use," according to a statement by the ministry. The plague has now affected 65 towns, up from the 45 that had been earlier reported, the statement said.