Human: What is the best way to keep a hummingbird feeder filled? Assistant: 
The best way to keep a hummingbird feeder filled is to make sure it has plenty of nectar and sugar water. Make sure to change the sugar water every few days and clean the feeder regularly to remove any debris that may be clogging the feeders. Additionally, you can try placing the feeder in an area with good visibility for the hummingbirds so they can easily spot it.