Snake Found on Alaskan Airlines Flight

Do you remember the movie “Snakes on a Plane” with Samuel L Jackson? Well passengers on an Alaskan Fight encountered a 4 foot long albino boa constrictor under someones’ carry-on bag. Flight attendants managed to wrangle the snake into a garbage bag, where it stayed until the plane landed.. I want to know how the snake got smuggled onto the plane in the first place?