Bill who putters wrote:

-snip-
Nan have the tried the upside down Niger tube feeder? It forces the
finches to flip upside down to feed. Neat as only finches can do it.

and the occasional Chickadee. I had 1 the first year & now there are
at least 2. It is funny that other chickadees will sit on the
other perches and seem to be thinking 'How in hell are you doing
that?'.

Jim