Stinky coop? Stop by the farm & grab a bag of BIOCHAR! 
"An immediate use of biochar in poultry farming is to reduce — and even eliminate — odors from poultry litter, particularly ammonia. Biochar adsorbs gases, liquids, and ions, and ammonia (NH4+) is all three. Adsorption is the adhesion in an extremely thin layer of molecules to the surfaces of solid bodies or liquids. Activated carbon’s effectiveness for odor control is well-known and is preferred in air purifiers. Farmers can spread a blend of 5 to 10 percent biochar with conventional litter on a barn or coop floor.
Ammonia’s strong positive electric charge makes it corrosive and toxic to breathe. This gagging gas is emitted by bird droppings, creating air that is unhealthy and toxic to birds and humans. Ammonia irritates skin on contact and degrades even hard tissue, such as hooves. It also attracts insects, such as flies. This is one reason biochar can even serve as a fly deterrent."