This happened to my ice cubes a few years ago, and I learned that this is because the water freezes unevenly. The liquid in the middle of the ice cube starts to seep out of a small, unfrozen hole. If conditions are just right, the water freezes as it leaves the hole and gives you an ice spike.
With a bit of imagination, I think that the ice spike looks a bit like a hummingbird. Maybe it’s time to think about refilling the feeder? I think it’s getting warm enough that the sugar-water won’t freeze.
An ice spike that I found in an ice cube in 2005.