[dudul]

Why would you prank them at all? They are showing up to do their job, not be your buddy from college.

You have no idea how they will react to your "prank". They could feel rejected and/or humiliated. It could literally make them quit on their first week. Good job wasting the company thousands of dollars for your little prank.

Prank your friends, prank your coworkers who happen to also be your friends if you want. Don't prank strangers when they're already going through the stressful event of starting a new job.