Yes. Pasty butt. I use clean, warm water to clean the vent area with. Often the problem disappears. If you type in "Pasty butt" in the advanced search box at the top of this page many threads/ posts will become available to you. After you clean the vent area check the skin color in that place. If the skin looks very red and swollen, the chicks may have an intestinal infection that needs to be treated with antibiotics.