During our holiday at Kynance Cove in Cornwall a few weeks ago, I came across this impressive Bloody-nosed Beetle (Timarcha tenebricosa), a large leaf beetle, alongside the brook that runs down to the shore. One source describes it as a great clunking clockwork model of a beetle:
It should properly be called the Bloody-mouthed Beetle because, when threatened, it will exude a bright red substance from its mouth (not its nose). Personally, I've never tasted it but I'm assured that birds and other predators find it absolutely disgusting, putting this wee beastie off the lunch menu forever afterwards!
The Featured Creature Website has collated some impressive photos of this species in the act of exuding its foul fluid, including a bit of video!