Tools & chemicals:
Use only water and a stiff brush since birds are sensitive to chemicals.
Technique:
Clean bird feeders thoroughly every 2 months by emptying and rinsing with water. Use a stiff brush on wood feeders. Use a brush and hot water on plastic feeders. Use only water since birds are sensitive to chemicals. For hummingbird feeders rinse and clean often since the sugar water can create mold and bacteria quickly.