A few butterflies and many moth species spin a silk case or cocoon prior to pupating, while others do not, instead going underground. A butterfly pupa, called a chrysalis, has a hard skin, usually with no cocoon.
4. tension - (physics) a stress that produces an elongation of an elastic physical body; the direction of maximum tension moves asymptotically toward the direction of the shear. natural philosophy, physics-the science of matter and energy and their interactions; his favorite subject was physics.
The strategy of tension (Italian: strategia della tensione) in any language, even as reported by Wikipedia in an article dotted with claims for documentation that appear to be distractions, is a tactic that aims to divide, manipulate, and control public opinion using fear, propaganda, disinformation, psychological warfare, agents provocateur, and false flag terrorist actions.