We wanted to feed the birds since we knew we had a number of different kinds. The first thing we did was to try the suet cake. That immediately led to a major problem, that being the number of house sparrows that descended. They are bullies and chase other birds away. We also had a problem with a squirrel taking a chunk of the cake so we found another kind.
The second type of suet cake had very spicy stuff in it, so spicy that mammals will have nothing to do with it. The squirrel came up on the deck once, sniffed the new cake, turned around and left.
Yet the spicy stuff has no effect on the birds at all. Still, that didn't solve the house sparrow problem.
Next we went to a sort of small bird feeder with niger seed. House Sparrows don't care for that so that cut out that problem. The only disadvantage was that the only birds showing interest were the house finch and the goldfinch. The feeder openings were too small for the other birds and they also didn't care for niger seed.
We decided we wanted some of the other birds back so we got a large, squirrel-proof feeder which definitely works.
The moment the squirrel put his weight on the cap the cap moved down. This seals all the openings so the squirrel gnawed, got nothing, and left. He has tried again, with the same result.
One of the most amazing birds that showed up on the large feeder was this partially-albino cardinal. It's a really cute bird which took a while before he worked up the courage to eat at the feeder. Some birds are shy and take a while before they'll try it. Once they eat there, though, they keep coming back with no problem.
Then there are the other birds which include two types of woodpeckers, tufted titmice, nuthatch, house finch, goldefinch, cardinals and junkos, although the junkos like to eat the seeds spilledo on the ground by the other birds.
I also did a five minute video of birds eating at the large feeder. Sometimes it can get rather crazy.