USDA's meat and poultry inspection system is often called "continuous" because no animal destined for human food may be slaughtered or dressed unless an inspector is continuously present to examine each one before slaughter (antemortem inspection), and its carcass and parts after slaughter (postmortem inspection). In processing plants (as opposed to slaughter plants), inspectors need not be present at all times, but they do visit at least once daily. Thus, processing inspection is also considered to be continuous.