You are initially taken aback by this realistic drawing of a bat’s face, made by the 19th-century German biologist Ernst Haeckel. It strikes you as an odd-looking face, yet after gazing at it long enough, you will recognize that it is not so odd after all. You will see past the extravagant frills and flourishes to discern the elements of a human face. In the end, you will find it a bracing reminder of our kinship with all mammals, including these clown-faced bats.