Good question, Channy (in Cincinnati). Yes, it’s true both kinds of feeders may attract a rare to uncommon visit by some wood-warbler species, such as seed eating Yellow-rumped and Pine Warbler. Nectar sometimes coaxes wood-warblers with longer bills such as Cape May, Orange-crowned, and Virginia.
That written, the vast majority of wood-warblers typically abstain from visiting feeders. Most maintain a nearly-total insectivorous diet, so stay away from feeders.
As for suet feeders, I’ve seen the above species at suet, in addition to Townsend’s.
How about you and other readers? You have seen wood-warblers at feeders? Please let me know at DanielEdelstein@att.net
Lastly, my web site — WarblerWatch.com — has more information several bird topics via the “Birding Links” pulldown menu. Information about my birding tours is at the “Birding Tours” area.
Happy Holidays to everyone…!