
Darkness also plays a role. Lizards generally avoid laying eggs in bright, exposed areas. Direct sunlight can overheat eggs, while open spaces increase the risk of predation. The shaded area behind a bed remains dark for most of the day. This darkness may make the location seem ideal from the lizard’s perspective.
Humidity can be another contributing factor. Reptile eggs require a certain amount of moisture to develop properly. Excessively dry environments can cause eggs to lose water and fail to hatch. The area behind furniture sometimes traps a small amount of moisture and experiences less airflow than open parts of a room. This slightly more humid environment may help protect eggs from drying out.
A female lizard may also return to a location if it has been used successfully before. Some species exhibit what scientists call communal nesting behavior. This means multiple females may deposit eggs in the same protected location over time. If a hidden area behind a bed has previously served as a successful nesting site, future lizards may continue using it.