why do you need roach for a joint
Roach (smoking) In Europe, the United Kingdom and most Commonwealth nations, the term is often used more specifically to refer to a short tube, commonly torn from a pack of rolling papers, that may be present in the unlit end of a joint.[citation needed] This hollow mouthpiece, customarily made of thin cardboard, is termed a filter in North America. In other parts of the world other materials are also used, e.g. steel. The steel roach was invented to fill the gap of reusable product category and it also does not have as much crystal deposits like paper filters. It is commonly set in position during the rolling process, or may be inserted later. When the use of a roach is employed, a joint can still be held securely after it has burnt down to a short length; thus, the entire length of the joint may be smoked, without the aid of a roach clip.[1]
Spiracle Insects and some more derived spiders have spiracles on their exoskeletons to allow air to enter the trachea.[4] In the respiratory system of insects, the tracheal tubes primarily deliver oxygen directly into the animals' tissues. The spiracles can be opened and closed in an efficient manner to reduce water loss. This is done by contracting closer muscles surrounding the spiracle. In order to open, the muscle relaxes. The closer muscle is controlled by the central nervous system but can also react to localized chemical stimuli. Several aquatic insects have similar or alternative closing methods to prevent water from entering the trachea. The timing and duration of spiracle closures can affect the respiratory rates of the organism.[5] Spiracles may also be surrounded by hairs to minimize bulk air movement around the opening, and thus minimize water loss.