If you wait for bullying to occur it's too late. You need to proactively address the issue. Here's how - 

• Familiarize yourself with bullying 
• Talk to your team about bullying - show it's a topic you care about  
• Define the different, even subtle forms of bullying 
• Explain unintentional bullying 
• Explain second hand abuse 
• Explain what you want people to do if they feel bullied 
• Explain what you want bystanders to do if they witness bulling 
• Explain what you'll do once you observe or become aware of bullying