How It's Made simplify overdubbing in different languages. For example, the show currently avoids showing a narrator or onscreen host, does not often have employees of featured companies speak on camera, and keeps human interaction with the manufacturing process to a bare minimum. An off-screen narrator explains each process, often with humorous puns. Each half-hour show usually has three or four main segments, with each product getting a demonstration of approximately five minutes; exceptions are allowed in the allotted time for more complex products. Usually, every show has at least one product with a historic background note preceding it, showing how and where
Whiskers these whiskers is not random: they form an ordered grid of arcs (columns) and rows, with shorter whiskers at the front and longer whiskers at the rear (see images). In the mouse, gerbil, hamster, rat, guinea pig, rabbit, and cat, each individual follicle is innervated by 100–200 primary afferent nerve cells. These cells serve an even larger number of mechanoreceptors of at least eight distinct types. Accordingly, even small deflections of the vibrissal hair can evoke a sensory response in the animal. Rats and mice typically have approximately 30 macrovibrissae on each side of the face, with whisker lengths up