Boys don’t fear expulsion, suspension, or the cane because they know we work very hard to make sure those punishments are never unfair – we’re not perfect, I admit that, I know of a few cases where innocent boys have been caned despite our best efforts – but we’re as close as is practical to that. The punishment they regard with concern is detention, because they do think that can be unfair. Some people are trying right now to find a practical way of dealing with that.
There’s also the factor that our school has one of the lowest levels of bullying of any school identified here. And part of the reason that is true (and it’s only part of the reason) is the fact we have the cane and we use it, where appropriate, with bullies.