I'll stick my 2 cents in. I had ducks years ago and never had a reaction. Fast forward 20 yrs. I built a pen out of treated wood. It's an open pen with 1/2"x1/2" hardware cloth w/a tarp over a ridge beam. I stain it too. Baby ducks arrived while I was working on the pen. I started to break out on the arms, I thought I had prickle heat. It took awhile, but it started to travel on my body. Went to the Dermatologist and she said I had an allergy, (I could have told her that). Everytime I go near the pen, (which is several times a day) I start to itch. I don't think it's the eggs, because it started well before they started laying. I thought it might be the chemicals in the treated wood, mixed with the stain I used. The pen was put up last April, it is now Feb, 10 months later. I don't know if it's the ducks or the pen??????????????????????? I should think by now with all the rain and cold any chemicals would have disapated. Now I'm thinking it's the duck poop, which gets cleaned everyday. Any thoughts? The body changes. One day your not allergic and the next day you are.