The roles that the medium- and micro-predators play in ecosystems were first noted by Darwin. He observed that field mice prey upon "humble" bee nests, and that the abundance of cats in a district, through suppression of mice, may increase the flowering success of certain plants, such as clover. Here, Aaron Greenville, Katherine Tuft, Rob Brandle and Chris Dickman discuss how the Australian arid zone is an ideal place to examine Darwin's observation and its implications as they undertake research to help secure the future of the kowari.