Other dangers arise from efforts to control rodent populations. "One example is when people use these anticoagulant rodenticides (rat poison) to kill mice. Those toxins can accumulate in owls and actually kill them," says Seth Magle, director of the Urban Wildlife Institute at Lincoln Park Zoo, a research center that studies animals in cities around the world, including Chicago, to understand how humans and wildlife can coexist. "I'd like to see people using different rodenticides that aren't quite so hazardous. But, at the same time, you can't tell people not to control these rodent infestations around the home. I think it's up to us as a society to try and investigate different ways of doing that."