The Ladder snake is a medium large snake, older females possibly attaining 1.7 metres, but 1 metre is the average length. Their head is quite prominent and distinct from their body, almost a squashed egg shape, small non prominent eyes with round pupils. The adult colour is uniform, shades of greys or browns, the back well marked with two darker longitudinal parallel bands. Juvenile snakes are much lighter in colour varying from yellow to light brown, with the characteristic “ladder” pattern, from which the name is derived, picked out in black along their back. The pale underside has black markings which sometimes coalesce to cover the whole of the underside. As they age these colours and patterns fade until the simpler adult pattern is left.

In France they are only to be found in the south where preferred habitats are dry and sunny, often slightly barren, with bushy scrub. Prey is mainly small mammals but birds, insects and lizards are also taken. Older, larger snakes will kill fairly large prey by constriction. Juveniles prefer small lizards, baby rodents, spiders, and grasshoppers.

Although mainly diurnal they will also hunt at dusk and during the night in hot conditions, the young are nocturnal. Being discrete and fearful they flee from any disturbance taking cover in a hole in the ground or hollow tree, however they become extremely irritated when cornered, hissing furiously and sometimes "biting" if handled. Very susceptible to cold – hibernation takes place from October until April.

Coupling takes place in April / May or a little later at higher altitudes or if weather conditions are poor. About 12 eggs are deposited under an old tree stump or a layer of pine needles in July, hatching can take anything from 6 to 12 weeks dependent upon the temperature.