How do I keep hummingbird feeders from freezing?

Anna's hummingbirds frequently overwinter in the Lower Mainland. Help them survive in freezing temperatures by keeping their food available. The recommended sugar to water ratio is discussed for nectar as well as ideas to prevent it from freezing. Keep your Anna's hummingbirds safe and be there for them when the temperatures dip below zero.
Some excellent information can be found on the Rocky Point Bird Observatory website, http://rpbo.org/hummingbirds.php#
For information on how to make heaters, you can find it here: http://rpbo.org/reports/Supporting_Resident_Anna's_Hummingbirds_During_Winter_Months.pdf
NEW - For the most important things to do in cold snaps, watch here:
https://www.youtube.com/watch?v=tlr9PvreQPw&t=11s

Видео How do I keep hummingbird feeders from freezing? канала Tara Leigh