I second the above posts really - when used in education or in a crowded environment it would be a basic idea to have a snake you know would be calm and unstressed by the conditions.
You have to always have to hope for the best but plan for the worst - what would happen if the snake got freaked out and bit someone - we all know it's not a big deal but reassuring parents and children with challenges of that might not be as easy as you think.
just my 2p ( uk term ;P )
dr del