Unlike most other birds, hummingbirds need sugar water as bird food instead of seeds and grains. Hummingbird diets are mostly made up of flower nectar. Sugar water is the best substitute for flower nectar. In order to make your own food for hummingbirds, sugar water needs to be boiled for about two minutes. This helps sterilize the water.
Hummingbirds are much smaller than other types of wild birds so it takes very little in order to get them sick or kill them. Tap water contains microscopic amounts of fungal spores and bacteria. Even if the tap water does not get a person sick, it contains more than enough bacteria and fungal spores to kill a hummingbird. Boiled water also spoils slower than tap water, according to the Audubon Society. Spoiled sugar water grows molds and bacteria that can potentially be fatal to hummingbirds.
Only boil sugar water by means of a stove. Combine 1 part white granulated table sugar to 4 parts water. Bring to a boil. Cover the water pan so the water does not boil away; this also prevents the sugar water from turning into a sugary sludge or becoming solid, according to the book "Hummingbirds of North America: Attracting, Feeding and Photographing." After two minutes, turn off the heat, and allow the hummingbird food to cool. Fill nectar feeders, and refrigerate any extra.
Do not use a microwave to boil sugar water for hummingbirds. Microwaves cause the sugar molecules to break down and change their chemical structure. Hummingbirds will still drink the solution because it tastes sweet, but it may not give them the calories they need to survive.
Bees love sugar water set out for hummingbirds and can become a nuisance at feeders. Bees tend to prefer taking nectar from flowers with a slightly higher sucrose percentage than hummingbirds prefer. If bees are a problem at a hummingbird feeder, use five parts water instead of four. This will not be sweet enough for bees, but sweet enough for hummingbirds, according to the University of Kentucky.