The avian flu is back in Texas. Texas Parks and Wildlife announced on Tuesday that a backyard flock of poultry in Dallas County tested positive for the disease. Avian flu is usually spread by wild waterfowl that act as carriers and don't have symptoms. But they can infect domestic birds like chickens through direct contact, or via contaminated cages, water, and feed. The risk of human infection is currently low, but state wildlife experts are warning hunters, urban farmers, and animal rehabilitators to proceed with caution around wild birds.