An active predator, the diadem snake predominantly feeds on rodents, throwing a loop of its body over its prey to immobilise it, before delivering a suffocating bite with its powerful jaws (4). Like some other Colubrid snakes, this species also produces chemical secretions from an oral gland, which are highly toxic to small mammals, but pose no danger to humans (2) (7). In addition to rodents, the diadem snake is also known to prey upon lizards such as agamas, and occasionally on small birds (2). When threatened this species is known to inflate and thrash its body, hiss and make rapid strikes (2) (4).
The diadem snake changes its activity period according to the season. It is diurnal during the winter, autumn and spring, but becomes nocturnal and crepuscular during the summer, resting amongst stones, loose rocks, desert plant roots or in rodent burrows during the day to avoid the extreme heat (2) (8).
Diadem snake courtship takes place in spring, with the females laying between 3 and 16 eggs, around 67 days after mating. Usually only one clutch is laid per year, but occasionally two separate clutches are produced, the first in early June and the second in early September. Incubation normally lasts for around 60 days, with the young born measuring between 36 and 42 centimetres in length (2).