Mediterranean house geckos don’t truly hibernate, but they do enter a dormant state called brumation during cold months. Unlike hibernation in mammals, brumation is a lighter form of dormancy where the gecko’s metabolism slows dramatically but the animal can still rouse itself during warm spells. In warmer climates or heated buildings, some populations skip extended dormancy altogether and remain active year-round.
Brumation vs. Hibernation
Reptiles don’t hibernate in the way bears or ground squirrels do. Instead, they brumate. The key difference is that brumating animals aren’t in a deep, uninterruptible sleep. Their metabolism drops, they stop eating, and they become sluggish, but they can wake up and move around if temperatures rise temporarily. A Mediterranean house gecko in brumation may go days or weeks without moving, then crawl out on a mild evening before retreating again.
This flexibility is part of what makes these geckos such successful invaders. They originated in the warm Mediterranean region but have spread across the southern United States and other temperate areas, partly because their dormancy strategy is adaptable to local conditions.
What Triggers Dormancy
Temperature is the primary driver. Related house gecko species lose motor control at critical thermal minimums between roughly 8°C and 11°C (46–52°F), and Mediterranean house geckos appear to have a similar threshold. When ambient temperatures drop near or below this range, the geckos become unable to hunt, digest food, or escape predators effectively, so they seek shelter and slow down.
Shorter daylight hours and reduced insect availability also play a role. Even if a warm day occurs in December, the gecko may not find enough prey to justify full activity, reinforcing the tendency to stay sheltered.
Where They Shelter in Winter
Mediterranean house geckos typically brumate inside the walls of buildings, under debris piles, in rock crevices, or behind exterior fixtures like shutters and light housings. Their close association with human structures is a major survival advantage. Wall cavities and attic spaces stay warmer than outside air, buffering the gecko against lethal cold snaps.
Research on populations near the northern edge of their range found that temperatures inside wall crevices still dropped below the geckos’ expected critical thermal minimum during January and February. Yet the geckos survived and went on to reproduce successfully in spring. This suggests they can tolerate brief exposures to temperatures that would normally impair them, as long as they have insulated shelter to limit how cold they get and how long they stay there.
Year-Round Activity in Some Populations
Not all Mediterranean house geckos brumate. A study at the University of Central Oklahoma, near the species’ northern range boundary in the U.S., found geckos active during 42% of winter censuses when air temperatures were at or below freezing. On one occasion, a gecko was spotted when the air temperature was a remarkable -8.3°C (about 17°F). The researchers concluded there was no population-wide dormancy at this site, even during the coldest months.
The likely explanation is that geckos in these northern populations shift their activity indoors, using heated buildings as thermal refuges. A gecko living inside a climate-controlled warehouse or behind a warm exterior wall may never experience temperatures low enough to force brumation. In the southern U.S., geckos are commonly seen active on the outside of buildings during warm months and occasionally inside buildings during winter.
What to Do If You Find a Sluggish Gecko
If you discover a Mediterranean house gecko in your home during winter and it appears lethargic or barely moving, it’s almost certainly cold rather than sick. These geckos are ectotherms, meaning their body temperature matches their surroundings. A cold gecko will be slow, unresponsive, and may look dead, but it’s likely just in a torpid state.
If you’d like to help it, place it in a sheltered spot where it won’t be stepped on or attacked by pets. A cardboard box near (not on top of) a warm wall works well. Don’t place a cold gecko directly on a heat source, as rapid temperature changes can stress reptiles. If you’d rather it live outside, wait for a mild day and relocate it near a wall crevice, rock pile, or other sheltered spot where it can find its own refuge.
These geckos are harmless, eat insects like cockroaches and moths, and are generally considered beneficial around homes. Many homeowners simply leave them alone and see them reappear on exterior walls once nighttime temperatures consistently stay above about 15–20°C (60–68°F) in spring.
How Long Brumation Lasts
The duration depends entirely on local climate. In the Gulf Coast states, geckos may only slow down for a few weeks in the coldest part of winter, with intermittent activity on warm nights. In more northern locations like Oklahoma or Arkansas, reduced activity can span from late November through early March, though geckos using heated buildings may remain active throughout. In their native Mediterranean range, mild coastal winters mean brumation is typically brief and shallow, with geckos emerging on any night warm enough to hunt.