The Common Shrew (Sorex araneus) shrinks its head by up to 20% to survive winter. Come spring, their heads return to roughly normal size. #animals #facts #friends https://t.co/tH0NMUugZUThe Common Shrew (Sorex 7474098 The Common Shrew (Sorex araneus) shrinks its head by up to 20% to survive winter. Come spring, their heads return to roughly normal size.