Snake on a plane?

I have a character, teenager, going to live with an aunt for the summer. She (the teenager) owns a pet snake and wants to bring him with her. I have her flying to get to her aunt's house. Can she take the snake with her? I know you used to be able to bring small pets (dogs, etc.) on the plane as long as they could fit under the seat, and I once brought my much larger dog (he rode in his crate with the luggage.) But with the new security rules and all, could she bring a snake? I'm flexible as to the type and size of snake, although slightly on the large size would be more fun (aunty is afraid of snakes.) Snake could easily travel in a plastic container, and the container could be of the size that could fit under the seat in front of her. And - my daughter (who has a red-tailed boa) just said she heard something about new laws in the works to prevent people taking snakes over state lines. Anybody heard of that? How on earth could you enforce that? Her snake came from a couple states away via a large reptile show.

Any info would be helpful. Thanks!