Here are some pictures of the birds that like suet and peanuts, mostly those that naturally make much of their living getting insects out of tree bark.
I’m not sure why, perhaps some people who know more about it can comment, but they differ in their preferred orientation while feeding.
The nuthatches prefer heads-down, at 180º from my preferred feeding orientation.
Chickadees seem more sensible to me.
The small woodpeckers are often the “right way” up, but as the level goes down, they switch to a horizontal orientation.
The rose-breasted nuthatches are also upside-down feeders but here are shots as they get ready for dinner; nuthatches at least land the right-way up, before turning over. On trees, they also run downwards after landing. Do they ever crash, beak-first, into upwardly mobile woodpeckers?
It was -27ºC when I got up this morning, but as it was a nice sunny day, the temperature soon soared to -12. So the birds’ feathers were well fluffed-up.