Bees, particularly those in new hives, require a lot of energy to draw out comb. To help jump-start the hive, a 1:1 sugar syrup can be used to help feed them during this time. I'm pretty certain they could make it without this feeding in the spring assuming there were sources of nectar around. But, since my hives are new and I'm not expecting or planning to take any honey this year, I'm OK about feeding them sugar syrup to provide them with the food they need to draw out comb on the frames this year.
I started with baggy feeders but they are a bit messy and quite honestly I don't like them because they are really a one-use feeder. I've got a bunch of canning jars and those can be reused so I'm trying some 1-quart jars in my hives as feeders. All one has to do is punch some small holes in the lid (I tapped a nail into the lid just a bit so that the smallest of holes was made.) and fill the jar with sugar syrup. With the lid screwed on tight and inverted over the hole in the inner cover a vacuum is formed and the syrup will not run out. The bees can then slowly eat the syrup. When it's emptied, I can just swap it out for a new one without disturbing the hive much at all.
Matt (twitter @MattInTheGarden) is a big fan of Punch Brothers and the music of Chris Thile in general. If putt putt doesn't count, he has never played golf. This time next year he'll be one year older.