Not eating while they are is also fun. I had a conversation at lunch with one who asked if I'd brought food that day (I rarely do anyways) and I responded that I was planning on going to a bar that evening and didn't want to eat lunch on top of the calorie bomb I knew it was going to be.  All the humans within earshot didn't seem to care or think twice about it, but the awkward tension from the ham was palpable.