This will keep ants off your hummingbird feeders. Many feeders have a built-in ant moat, some do not. Fill this with water. No ants! This one is clear, you can see the water level. Some birds may even take a little drink from it.

Comes with a hook on top to hang, and an S hook on the bottom to attach to the hummingbird feeder. Some folks like the red one which is on this page.