Vocabulary: invasive (adj.), crop (n.), to grow back (phrasal verb), unlike (prep.), steep (adj.), soil (n.), to clean up (phrasal verb), cemetery (n.).
The US is famous for its weapons, but this time they are using something a bit unusual to fight their enemy: goats.
The goats are used to kill poisonous and invasive species of plants that destroy farms and crops. In particular, they are used to eat Poison Ivy and a plant called Kutzu. This plant is originally from Asia, but causes lots of problems in the south of the US (Mississippi, Alabama and Georgia) because it grows very quickly: a foot (30cm) a day.
Goats are used to eat all of the plant until it cannot grow back again.
Typically chemicals or machines have been used to kill the plants, but goats are much better: unlike machines, they can go up steep mountains and into forests and unlike chemicals, they do not harm the soil.
The goats were even used to clean up the Congressional Cemetery in Washington DC.