I've never purposefully killed a snake, venomous or otherwise. I prefer teaching kids not to mess with native fauna and if they're too young to understand should they even be tramping around on their own where there could possibly be danger? These animals don't have malicious intent, I just don't see the justice in killing them. What happens when you're not there and the kid sees a snake? Will they pick up a stick or run get a shovel and try to take it out to "protect" themselves? Seems to me this would just be increasing the odds of getting tagged. Teach by example, kids are never too young to learn, and think hard about what kind of message you want to convey to protect and promote wildlife.