When it is disturbed or grabbed, it makes a sharp rasping noise with its thoracic segments. Then, if its thorax is pinched, it gives off a toxic foam. It squirts a clear viscous mucus with unpleasant smell and a bitter taste, faintly alkaline, with many bubbles. This foam comes out as a strong jet from openings in the thorax, and more gently from other openings in the body (ten in total). The foam heaps up around the insect and partly covers it.