I was trying to get some photos a couple weeks ago of the nuthatch that comes to my bird feeder, but he's very shy. So instead here are a couple shots of two of the sparrows who try to devour all the seeds.
Sparrows rely on strength in numbers. They do everything in groups of at least five, and they intimidate other birds in order to get what they want. What they want is all the seeds. Sometimes I deliberately leave the feeder empty for a week. When I finally refill it, the chickadees, nuthatches and rose finches get to eat for days before the sparrows figure out I refilled it. They descend upon it and can empty it out in two days, sometimes less if there are a lot of them.
If you look closely, you can see that some of the perches have been chewed off by squirrels. I bought an expensive bird feeder once. The squirrels destroyed it. Now I buy $5 feeders from Ocean State Job Lot and reinforce the handle with steel wire, then secure the handle to the hook with more steel wire. The squirrels have tried to chew through the wire, but it's too much for them. They've tried chewing the feed openings to make them bigger, but I guess that was also too much work for them.