On Mar 18, 4:20*am, wrote:
I have a fridge\freezer with an ice maker. The automatic ice maker
storage got high and a single ice cube got
placed behind the large storage tray, it has sat there for a while,
but started getting smaller, now it is
almost nothing.

What causes this cube to get smaller in an environment that appears to
stay the same?

Same reason water evaporates in an environment that appears to stay
the same. Solids can evaporate into gas. Dry ice is famous for doing
that.

PD