The loss of open spaces caused animals, such as bison and elk, to become scarce. Wolves began to hunt cattle and sheep in order to survive and feed their packs. Unfortunately, many of the people who settled the West didn't have resources to spare. The loss of even a single milk cow could mean the difference between survival and starvation for a struggling family. Even for the more prosperous, livestock damage due to wolves soon became an economic problem. This sense of competition led to an "either them or us" mindset that became ingrained.