In order to maintain their body temperatures, Chickadees must take in a large number of food calories which will be metabolized for body heat. Calder (1974) notes that Black-capped Chickadees ... must eat continuously during short daylight hours to stoke their metabolic fires.
Industrial sewing machines are the best option for sewing upholstery-grade fabrics such as vinyl and leather because these machines are designed to handle thicker fabrics. Industrial machines use heavier upholstery thread and often sturdier needles which penetrate the material cleanly.
Trainees often begin as machine operators and gradually take on more difficult assignments. Machinists and tool and die makers must be experienced in using computers to work with CAD/CAM technology, CNC machine tools, and computerized measuring machines. Some machinists become tool and die makers.