Think about how they are hung, as well. I know the house-style of feeder you're talking about, but I've had better luck with just hanging suet cake in a little wire cage that can be hung in a tree, close to the trunk. The woodpeckers and nuthatches love it because they just climb up and down the branches like they normally would and but reach the suet. We have several regulars and while the red-bellied woodpecker will go to the hanging feeders for sunflower seeds, the downy woodpeckers and the nuthatches only come to the suet that they can reach from a tree branch.
This made me LOL. There is no such thing as old seeds. Food is food for wild animals.
This made ME lol.
Birds can be picky as fuck.
Birds can be picky, yes. I mentioned that they leave the red millet seeds in the feeder at my house. BUT, some wildlife will eat it. The red millet seeds get eaten eventually when that's the only thing left for a couple days/weeks. Same with moldy produce like lettuce or strawberries. I leave it in my yard and it's gone the next day.
Woodpeckers peck the shit out of my Tudor house which is basically encased in wood on the outside (why 1991 construction? Why would you think this is a good idea?). I tried feeding them on the tree farthest from the house, they didn't care they still peck.
So if you have any wood on the outside of your house, don't encourage the woodpeckers lol.
I only feed the birds and squirrels so my cats have entertainment!
But yes, they are picky AF, and I love them for it.
When I bought my first feeder, I told myself it was for the cats. I tell the cats when I've fed "their birds." I even have one feeder specifically positioned by a window they sit in. But now that I'm up to about 10 feeders, I can't really say that it's all about the cats. LOL
Here's Mulligan sleeping through visits from nuthatch and a titmouse (I think).