The poison ivy/oak/sumac urushiol oil can be spread on clothes, skin, and many other things and can remain for years. The best product that I've ever used is Tecnu, which actually gets rid of the oil. I'm extremely allergic to poison ivy/oak/sumac, and this product has been a lifesaver.
You might call them to see if the chicks could be wiped down with Tecnu, if they seem to be covered in the oil. I once had some puppies who kept reinfecting me because they kept getting into poison oak. It actually caused me to lose my job because it spread so badly; I was even having trouble breathing and had to get a cortisone shot. (This was before I found Tecnu.) The original Tecnu could be used to wipe down clothes and the like to get off the oil; you'd have to see if the rest work that way as well.
Here's a link to what I've used. It looks like they've expanded with other products, too, so check them out.
http://www.teclabsinc.com/products.cfm?id=1F5604C8-9D05-4675-56129F6D83DF2417
Just fyi: I do NOT recommend any type of topical Benadryl product for itching because a doctor once told me that using Benadryl (whatever the ingredient is called) topically can make some people allergic to it internally, eventually. With my allergy to bee stings, some shellfish, and spider bites, I can't risk ever being allergic to oral Benadryl, as it's saved my life in the past.
Hope everything works out well.