What causes pieces of ice to stick to each other when left for a while? How do I prevent this?

well, the surface layermelts slightly when exposed to air above 0*C

 

when the ice is pressed together, the melted surface layer refreezes as heat is unable to reach it and is drawn away by the cooler layers of ice deper into the cube.

 

to prevent it, just make sure the temperatures the ice is exposed to are less than 0*C

Is there any type of water that do not have this property of sticking together? say distilled water? sorry if i ask again because i cannot keep it at below zero. i need to prevent it from sticking to each while being exposed at normal ambient temperature.

If the ice itself is just below freezing it shouldn't stick as well, since there is nowhere for the thermal energy to go and form new ice.

Even at precisely 0 C, brownian motion and equilibrium between solid, liquid and vapor will engender the same result given enough time in continuous contact. the only practical prevention is to keep the system mixed. Think about Icee and daiquiri machines and the purpose of continuously stirring it.

I saw this really great post today.thanks!