Now we've talked about the virtues of so-called pests like raccoons and skunks. But who keeps these omnivores in check when their numbers get out of control? Turns out it is one of the most reviled yet successful predators in the nation, the coyote. Humans have altered once-flourishing ecosystems, creating farms, cities and suburban sprawl, which has been a boon for rodents like rats, mice, and larger animals like raccoons and skunks. The consequences include an increase in disease and the downfall of other species like songbirds. Enter the coyote: Researchers have found that in areas where coyotes exist, there is a better balance of biodiversity and healthier populations of songbirds. Coyotes can be a problem animal for ranchers and urban cat and dog owners. Nevertheless, there are many ways that everyone can minimize the conflict they have with these "varmints."