Clean Your Feeders Before Refilling!
Generally, all you need is warm water and some sort of feeder brush that will allow you to scrub the inside. Rinse and dry thoroughly before you refill. If the feeder has any mold in it, or you have noticed sick birds around the feeder, consider cleaning the feeder with a solution of 1 part bleach to 10 parts water. Rinse thoroughly and dry. Check out our line of Wild Birds Unlimited brushes.
And remember, never add fresh seed on top of old seed!