We report preliminary data on the sleep ecology of Tropidurus hispidus (Tropiduridae) lizards based on six observations of sleeping lizards in natural settings, and highlight how standard monitoring techniques can be useful to study lizard sleep behaviour. We studied the sleeping habits and substrate use of three adult male lizards, monitored using thread bobbins, along with three adult lizards we found during active search (total n = 6). Monitored and non-monitored lizards were observed sleeping during the night with varied postures at variable heights. Regarding sleeping sites or substrates, we observed for the first time burrowing behaviour in sandy ground under thorny vegetation. Besides the use of the ground, four lizards used woody branches of shrubs for sleeping. We did not observe intraspecific aggregations during the sleep period. These preliminary results indicate that T. hispidus may rely on hiding and thermoregulating during sleep hours, which differs from other lizard lineages that are commonly found sleeping perched in thin vegetation or on leaves. We also highlight that the use of standard monitoring techniques, such as thread bobbins to study lizard sleep behaviour, enhances our understanding of the natural history of lizards and other reptiles. Keywords: behaviour, Caatinga, lizard, sleeping, tracking