I know very well that I'm supposed to post each idea separately, but these two ideas are strongly linked to each other and lemmuings wouldn't work without ice. The ice idea is from my sister Stagmole.   Ice: Ice only appears in mountain biomes. There are four weakness levels of ice. Normal ice doesn't have any cracks on it. Weak ice has one crack on it. Weaker ice has two or three cracks on it. The weakest ice is covered on cracks. If temperature is below 0, sea water freezes. At