This is my version of a DIY ant moat for a hummingbird feeder. I looked them up, and those question-mark-shaped screws are called either 'crown bolts' or 'cup hooks'. Very cheap at a hardware store or Target, etc. ...
by Shuddh Crafts Art
by Paper Folds - Origami & Crafts !
by village skills
by Pins and Things
by Mitanjali .M
by PK C.I.T.I
by Creative Ideas