An alligator is a security guard who has received highly specialized training that will allow him or her to handle any situation that might arise at any gate inside a buildings. Upon passing this course, alligators receive certifications that allow them to be legally contracted or hired to perform security services at all inside gates, hence the designation alligator.
Needless to say, this is a very highly specialized field. Alligators are not qualified to work at external gates at the entrances to buildings, campuses, barns or fenced-in areas. They are also not allowed to provide personal or property protection services. Before they can legally be hired or contracted to perform any of those services, alligators must first get the necessary additional extra training and certifications.