Explanation:
There are now many small soay sheep in Scotland because the winters are not as brutally cold as they use to be. The climate in Scotland has been warming therefore the sheeps of small stature can easily survive now in Scotland, which was not possible in earlier years.
The ice melts and it changes into a liquid state. Plus, the water droplets on the glass evaporated too.
1. gravity keeps the water moving downward or just in general
2. the water has to move across the surface for so long till eventually it just erodes away.
those are the only two i know sorry.
