Hatsan Hercules .357 and Hatsan Carnivore .30 cal air rifles taking out California ground squirrels and other pest legally on private property. Ground squirrels are serious agricultural pests causing damage from $30 to $50 million annually in California alone. They do much immediate damage, and also create problems that may surface later on. Damage ranges from chewing on trees and irrigation lines, eating crops, destruction from burrowing, and disease such as plague.