Rocky Mountain locust
The Rocky Mountain locust (Melanoplus spretus) is an extinct species of grasshopper that ranged through the western half of the United States and some western portions of Canada with large numbers seen until the end of the 19th century. Sightings often placed their swarms in numbers far larger than any other locust species, with one famous sighting in 1875 estimated at 198,000 square miles (510,000 km2) in size (greater than the area of California), weighing 27.5 million tons and consisting of some 12.5 trillion insects, the greatest concentration of animals ever recorded, according to Guinness World Records.