 As the spiny-tailed monitor has a lower level of activity compared to other monitor lizards, as well as a lower metabolic rate, it is often found in its hideout at day, and most likely it is a sit-and-wait-predator.They prey mainly on insects, most commonly orthopterans such as grasshoppers, followed by beetles and cockroaches.Small lizards such as skinks, geckos, or dragon lizards are also eaten, making up about a third of its diet.