system
Given the following post, respond as if you're commenting on Reddit:
human
Why does the ice in my ice cube tray sometimes climb upwards as if on an invisible wire?

This has been happening for years and years, different ice cube trays and different freezers. I will pour water in my ice cube tray and let it freeze and when I come back one or two of the ice cubes will have a stick of ice about 3cm coming out of the top, a little stick of ice.  Is it climbing an impurity somehow? This has always struck me as odd.  I have a photo but I'm not sure if I'm supposed to post those here.

Edit 1: I use cheap plastic ice cube trays and I have no idea the strength of the blower in my freezer, I have always rented so I just get whatever random freezer I get, but it's always happened.

Edit 2: All I have ever used for ice is unfiltered tap water.

Edit 3: Tanks for shiny silver!
gpt
The ice first freezes at the surface, and can result in a small "hole" of liquid at the surface, through which interior water is forced as more ice forms.  The water so expelled forms the spike as it freezes.