Apart from nectar, a hummingbird’s diet must also contain protein in it, as a hummingbird will die without it. Approximately 10% of a hummingbird’s diet is protein. A hummingbird can gain the necessary protein through the following: small arthropods such as gnats, spiders, mosquitoes, aphids, caterpillars, and insect eggs.
I wish to provide a brief word of caution here. It is vitally important that pesticides not be used whenever hummingbirds are around. Let your hummingbirds act as a natural exterminator for you by eating the bugs. Also, if a hummingbird eats insects with pesticide on them, the pesticide can make the hummingbirds violently ill or it may even cause the hummingbirds to die.
If you wish to do so, it is even possible for you to grow the bugs on which your hummingbirds can feed by doing the following:
Get any large, empty, clean plastic bucket that has a lid and punch a bunch of really tiny holes in the lid. If your container does not have a lid then you can use a piece of fabric that has been tightly secured as the top of the container.
Place the banana peels of one or two bananas in the bottom of the container with the lid off. After a day or two you will begin to see fruit flies around the fruit.
Now put the lid or the fabric on the top of the container, so that in time the bugs will start to breed, thus making more bugs. It is important that the bucket or container is not placed in direct sunlight.
Each day, at the same time of day, go to where your hummingbirds are and bring out the bucket. Take the top off the bucket very quickly to let out a few bugs and put the top right back on. The hummingbirds will soon begin to associate the bucket as being an easy source of protein.
If every few days you continue to add another old banana or apple in the bucket you will ensure that the bugs will continue to breed and thus there will be a continued source of protein for the hummingbirds.
I personally have never tried to grow bugs on which to provide the hummingbirds a source of protein, but I have read that it is possible if you should wish to do so. It seems like it would be too much extra trouble, but if you are in to doing things in a more natural manner this might be of interest to you. If you should try this, please let us know how it works.