The ladder snake (Zamenis scalaris) is a species of non-venomous snake in the family Colubridae. The species is endemic to southwestern Europe.
The geographic range of the ladder snake includes Portugal, Spain, southern France and just into Italy, also Menorca and the Iles d'Hyères off Provence, but it is absent from northern Iberia including much of the Pyrenees, Galicia (although the species is found on Ons Island, in the Atlantic Islands of Galicia National Park, Cantabria and the Basque Country. The population on Menorca may stem from an introduction by humans.
The Ladder Snake enjoys scrub bushy cover, including orchards, vineyards, hedges and overgrown dry-stone walls; it is common in the maquis. Habitats with stones and boulders and low shade are preferred. Although known at altitudes over 2,000 metres (6,600 ft), this is a species which prefers altitudes from sea level to 700 metres (2,300 ft).
