Chickens can get parasites- both internal and external. Some people get pretty creeped out by this.
You may need to purchase a "special" pair of shoes just to enter the run/coop. It's a special feeling when you show up at work and realize you've still got chicken poo stuck to your shoes. The feather stuck to it adds a nice touch, though.
You may find that some people - family, friends, coworkers - don't get as excited about your chicken stories as you do.