The thing about bulls is they have a rather intimidating threat display. Most snakes want to be left alone and if you let them chase you off they will just continue using that tactic for every encounter. Some hatch out calm, like the yellows I produced this year, but most are ready and more than willing to use every tool in their arsenal to chase off potential predators. It sometimes takes a bit more time to build trust with a bull but they can and will become calm individuals if you show some patience and understanding.