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 them understand how biological whiskers work and as a tactile sense for robots. These efforts range from the abstract, through feature-specific models, to attempts to reproduce complete whiskered animals in robot form (ScratchBot and ShrewBot, both robots by Bristol Robotics Laboratory). A range of non-mammalian animals possess structures which resemble or function similarly to mammalian whiskers. Some birds possess specialized hair-like feathers called rictal bristles around the base of the beak which are sometimes referred to as whiskers. The whiskered auklet ("Aethia pygmaea") has striking, stiff white feathers protruding from above and below the eyes of the otherwise slate-grey bird,