The Bombadier beetle (Brachinus crepitans), found in coastal Southern Britain from May to June, defensively sprays a heated mixture of hydrogen peroxide and hydroquinone when threatened. Charles Darwin famously experienced this defense mechanism twice while collecting beetles at Cambridge in the late 1820s, once placing a beetle in his mouth to avoid losing it to a third specimen. The related Crucifix ground beetle, now endangered, is nocturnal and found in only a few UK locations near water margins.