Armoured crickets have a bizarre and striking way to avoid being eaten. To become unpalatable, the insects squirt toxic blood out of gaps in their body and make themselves sick by throwing up food they've just eaten. A few insect species including beetles and katydids actively bleed when attacked, but the benefits of taking such extreme measures were not clear. Now scientists have shown the tactic really does work to deter predators such as lizards. Armoured ground crickets (Acanthoplus discoidalis) are fat, flightless insects that live in the African bush across Namibia, Botswana and South Africa. They are relatively large, growing up to 5cm long, have sharp spines across their thorax and legs and a pair of strong biting jaws. Males are also able to make a harsh loud noise by rubbing body parts together in a behaviour called stridulation.