African Armyworms are actually a type of caterpillar or moth found in Africa. The African Armyworm gets its name because it travels in large groups and can destroy acres of crops. In recent years the invasion of African Armyworms has traveled from Tanzania to Liberia. Outbreaks of the moth/worm have occurred in regions thousands of kilometers away from previous outbreaks, indicating the migratory capacity of the creature.BBC News: Q&A: Armyworms ravage Liberia (January 26, 2009)

In January 2009, Liberia declared a state of emergency because of an outbreak of African Armyworms. Concerns abound over food shortages as well as contamination of water sources from the invading caterpillars. The United Nations has indicated that if the outbreak is not contained quickly it could advance into Guinea, Sierra Leone and the Ivory Coast.United Nations: Food Security, Health & Environment at Risk... (January 23, 2009)

The African Armyworm are actually nothing more than the larvae of a breed of nocturnal moths. The females lay between 500 and 1000 eggs during the rainy season. Migration takes place during the night flight of the moths, which can be up to 60 miles per night. The hatched larvae like to feed on crop fields, growing up to 2 inches long. An army of the worms can destroy entire farms within days of their arrival.BBC News: Q&A: Armyworms ravage Liberia (January 26, 2009)