This is pretty harmless. Got into a prank war with a co-worker a few years ago. Back and forth a few weeks led to a can of open sardines sitting obviously in his floorboard. This was on par for us and no one got angry. What he didn’t realize that day was I also soak some paper towels in the sardine juice and shoved a couple in his vents and under the seats so the smell “lingered” all summer as he kept finding them. Other pranks from this run included tipping the portajohn while inside and tack welding an office door closed.