Study on seasonal changes of braincase depth of least weasels revealed, that similar to shrews, they exhibit winter shrinking of the skull and brain, followed by regrow in summer. This is common strategy of small, high-metabolic animals, dealing with massively changing food resources and weather conditions, which enables to increase their winter survival by decreasing maintenance costs of brain and internal organs. Full paper at: https://www.nature.com/articles/srep42443