Water snakes may not be poisonous, but they are still bad news to an endangered mole salamander. An invasive species in California, the snakes may increasingly pose a threat to native and endangered species in the state, according to research from the UC Davis Department of Wildlife, Fish and Conservation Biology.

The salamanders aren’t alone. Humans’ — and other primates’ — fear of snakes may be hard-wired. In 2006, UC Davis anthropology professor Lynne Isbell suggested that ancestral primates developed good close-up eyesight to avoid dangerous snakes, an idea recent research into snake-sensitive neurons has since supported.