People in groups love to celebrate. Some offices have done away with the traditional birthday cake at morning tea as the staff numbers grew because it became too difficult too disruptive, too hard to get everyone together or just too many people for one cake! This is sad. While the logistical difficulties of the birthday cake gathering might be prohibitive, this should not be a reason to forgo the one natural celebratory day that every staff member has. Put a sign at their desk, give them a special carpark for the day, use social media to get all colleagues to pass on a birthday wish celebrating this way doesn't have to be disruptive.