One iCloud account for multiple users I have my own iPhone and iPad and my boys iPods on an iCloud account. I've since added my boys iPhones on the same account so that I can monitor and control their apps and purchases. 

However I'm now getting calls and texts on my iPhone that are sent to them and when I send a text it shows as coming from their phones. 
Do I need to set up separate iCloud's to prevent this happening?
Yes. From Apple's perspective, one Apple ID = one person. If you want to share that Apple ID, it also means that all those sharing that Apple ID will have access to all the same things (purchases, texts, emails, etc.)

You may want to look into iCloud's Family Sharing, which allows up to six Apple IDs to be designated as belonging to one family. That allows the family to  share each other’s iTunes, iBooks, and App Store purchases without needing to share an Apple ID.