 Some changes have been made to a bill to allow those with residential properties to keep no more than eight chickens in their backyards. It must now undergo another public hearing. The Frederick County Council approved the amendment on Tuesday, which would require the portion of the backyard where the chickens are kept to have a fence at least four feet high. It would also require the chicken coops to be covered, ventilated, and predator resistant. The amendment was sponsored by Councilwoman Renee Knapp.