Why do people try not to laugh when they see me in a chicken hat?

I wore a chicken hat to work today. Aside from the obvious psychological problems I have, I noticed something today. The people I work closely with, all thought it was hilarious and loved it. All the way up the food chain. However, when we were all in the elevator, coming back in after lunch, we were in the elevator with people who were very talkative before they got on the elevator were completely silent on the elevator trying not to laugh.

I wore the hat to look ridiculous. It’s a damn chicken for god’s sake, complete with eyes, beak, and the red little feather things.

Why would they try not to laugh in the elevator? Are they afraid to offend me? My friend in the elevator said one lady turned and was smiling.

I don’t get it? Why not confront me about the hat?