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 About Technology
by Technology Teach Gear
by Lia Griffith
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by The Secret Life of my Hamster
by Cheshire Public Library
by You can do this