The Natterer's bat, Myotis nattereri, is a vesper bat and shows the unadorned face typical of this group. The Vesper family is the biggest and most widespread of all the bat families, with its 300 or so species ranging from the heat of the tropics to the cold winters of the temperate zones. They are found high up in mountains where vegetation begins to become scarce, as well as low down in tropical rain forests; they are in deserts and cities, in woodland and farmland on islands and inland--in fact they are everywhere except the coldest regions in high latitudes.