Dear Undergrad,
When I remind you that you should not be wearing gloves in the hallway/departmental office/computer lab (anywhere but at your research bench!) please do not respond with any of the following:
1. "Oh, I forgot I was wearing them."
2. Look at me, and then proceed to run your (gloved) hand all over the wall/door/keyboard.
or, my personal anti-favorite:
3. "But I didn't touch anything!"
Sincerely,
Dr. Reaction
