The Australian Thick-tailed Gecko (Underwoodisaurus milii) is a hardy, nocturnal native reptile known for its distinctive “barking” call and plump tail. When provided with correct heating, hiding spots, a varied insect diet and a clean, secure enclosure, they can thrive for many years in captivity – with a lifespan of 8 to 12 years and size of 10cm to 14cm. In NSW, they are a regulated native species, meaning a valid keeper licence and proper record-keeping are required. With simple, consistent care and respect for their shy nature, these geckos make rewarding companion reptiles for responsible keepers.
On This Page: Basic Thick-Tailed Gecko Information, Essential Supplies for Pet Thick-Tailed Geckos, Housing, Environment, Diet & Feeding, Behaviour & Handling, Common Health Concerns, Health, Hygiene & Safety, Record Keeping, Holiday Care, Transportation, Compatibility with Other Animals, Licensing, Helpful Reptile Keeping Links
Basic Thick-Tailed Gecko Information
The Thick-tailed Gecko is a small to medium-sized, ground-dwelling Australian native found across cooler southern regions, including rocky outcrops, grasslands and open woodland. Adults generally reach around 10–14 cm in body length. They are nocturnal, spending daytime hidden under bark, rocks or logs. In captivity they are considered a species well-suited for keepers with some reptile experience, although still manageable for beginners who commit to learning correct husbandry. Lifespan commonly ranges from 8–12 years with proper care.
Essential Supplies for Pet Thick-Tailed Geckos
Carry Enclosure: A sturdy, escape-proof and well-ventilated carry enclosure is mandatory for all reptiles leaving Birdsville. Carry enclosures are essential for any reptile transportation.
Secure Enclosure: A low, wide enclosure of at least 30 x 30 cm suits this terrestrial gecko well, with larger enclosures always welcome. Thick-tailed Geckos are active ground hunters, so floor space is more important than height. The lid must be secure and well-ventilated, as these geckos are surprisingly strong and agile for their size.
Substrate: Use a mix of non-silica sand and sifted peat moss, or a commercial reptile-safe substrate. Keep the substrate mostly dry, but lightly mist the cool end of the enclosure two to three times a week rather than keeping the whole substrate bone-dry. It’s important to spot-clean daily to remove waste or shed insect parts, fully replace substrate every 4–6 weeks depending on cleanliness, and stir the substrate occasionally to avoid compacting layers.
Food: A varied diet is essential – offer insects such as roaches, crickets, mealworms, and superworms. Keep insects in a well-ventilated tub with gut-load food to improve their nutritional value. It’s important to remove dead insects daily from the feeder container, keep insect tubs dry and clean to prevent mould, and rotate insect species weekly so diets don’t become repetitive.
Warm & Cool Hides: The warm hide sits directly over the heated zone so the gecko can digest food efficiently and regulate its body temperature. It should feel snug internally and be made of easy-to-clean material like resin, ceramic or smooth rock. The cool hide offers refuge when the gecko needs a lower temperature or feels threatened. This encourages natural behaviour and reduces stress. It should be positioned at the opposite end of the enclosure from the heat source. It’s important to clean the hide every 1–2 weeks, disinfect monthly, and check for cracks that may trap toes or tails.
Flat Rocks and Ground Décor: Secure flat rocks, cork bark, or low caves provide extra cover and hunting vantage points. Décor must be stable and unable to shift or crush the gecko if climbed on. It’s important to test stability after every deep clean, replace rocks that become chipped or loose, and not stack décor unless firmly anchored.
Heating Equipment: Thick-tailed Geckos require a warm zone maintained precisely using a thermostat-controlled heat source. An under-tank heat mat placed on one side only (allowing the gecko to move away from the heat) works well; overhead ceramic heat emitters are also suitable. It is important to test thermostat function monthly, check heating elements for hot spots or uneven output, replace heat mats every 2–4 years or when reliability drops, and never allow the gecko direct access to heating elements.
Digital Thermometers: Thermometers allow accurate monitoring of the temperature gradient. Digital probe thermometers are most precise. It’s important to reposition probes if readings look inconsistent and to clean probe tips with a dry cloth to avoid moisture.
Shallow Water Dish: Even hardy desert-adapted geckos must have constant access to fresh water. The dish should be shallow to prevent accidental drowning (especially for juveniles). It’s important to clean and refill daily, scrub with hot water weekly to prevent biofilm, and remove calcium residue with vinegar then rinse thoroughly, or use a pet-safe/veterinary grade disinfectant.
Supplements & Feeding Tools: Calcium, vitamin D₃ and multivitamin supplements are required, along with feeding tongs for safe and controlled feeding.
Reptile-Safe Cleaning Supplies: Dedicated disinfectant, sponges, brushes and paper towels are essential for hygienic care. Only use products safe for reptiles to prevent chemical irritation. It’s important to keep all cleaning supplies separate from household items, replace cleaning sponges frequently to prevent bacteria buildup, and rinse cleaned décor thoroughly and allow to dry completely.
Housing
A single adult requires approximately a 30 x 30 cm (or larger) enclosure with more floor space than height. This species can be kept in small groups – typically one male with one or more females, since adult males will fight if housed together. Provide a warm hide over the heated zone and a cooler hide on the opposite end. Smooth surfaces such as flat rocks (placed securely), cork bark, or low caves work well.
Environment
Thick-tailed Geckos are a cooler, semi-arid species and require a moderate thermal gradient rather than intense desert heat. The warm end should be maintained at approximately 27–29°C using floor-level heating, with the cool end sitting around 21–23°C at normal room temperature. Night-time temperatures may drop further but should stay within a safe range. Heating devices should be regulated by an appropriate thermostat to prevent overheating and reduce the risk of thermal injury. Humidity should stay low to moderate, with the cool end of the substrate lightly misted two to three times a week rather than kept fully dry. Adequate ventilation is important to prevent excess moisture build-up. A natural day and night light cycle of approximately 10–12 hours of light per day should be provided. As a nocturnal species with poor tolerance for bright light, dedicated UVB lighting is not considered essential, though low-level UVB may still support vitamin D synthesis if provided as part of a balanced husbandry program.
Diet & Feeding
Thick-tailed Geckos are voracious insectivores and should be offered a varied diet of appropriately sized live insects. Suitable feeder insects include crickets, roaches, mealworms, and other commercially available feeder species. Prey items should be no larger than the width of the gecko’s head. Juveniles generally require smaller, more frequent feeds, while adults can be fed larger prey every few days. Feeder insects should be gut-loaded 24–48 hours before being offered and dusted with calcium every two to three feeds, with a reptile multivitamin added weekly. Fresh, clean drinking water should be available at all times in a shallow dish and replaced regularly. Uneaten live insects should be removed from the enclosure after feeding to reduce stress and minimise the risk of injury to the gecko.
Behaviour & Handling
Thick-tailed Geckos tolerate moderate, gentle handling better than some other gecko species, though handling should still be kept to sensible levels to avoid stress. Never grab or restrain this species by the tail, as it will readily drop it as a defence mechanism – though the tail can regenerate, doing so takes significant energy and may temporarily affect the gecko’s condition. Their distinctive “barking” vocalisation is a defensive warning rather than a sign of aggression, and is one of the more memorable traits of keeping this species. Enclosures should provide multiple secure hiding places to support natural sheltering and foraging behaviour.
Common Health Concerns
Thick-tailed Geckos are generally hardy reptiles when their environmental and dietary requirements are met. Most health problems in captivity are associated with incorrect husbandry, including unsuitable temperatures, poor nutrition, inadequate hydration, or improper enclosure conditions. Regular health checks and appropriate husbandry practices can help prevent many common illnesses and allow potential problems to be identified and treated early.
Dehydration: Thick-tailed Geckos can become dehydrated if they do not have access to fresh drinking water or adequate humidity. Signs may include sunken eyes, wrinkled skin, lethargy, and loss of condition. Fresh water should be available at all times and changed regularly.
Heat Stress and Burns: Excessive temperatures or poorly regulated heating equipment can cause heat stress, dehydration, and thermal burns. Geckos may become restless, lethargic, or attempt to escape excessively warm areas. A suitable thermal gradient should be provided so the animal can regulate its body temperature.
Respiratory Disease: Respiratory infections can develop when enclosures are too humid, poorly ventilated, or maintained at inappropriate temperatures. Signs may include wheezing, open-mouth breathing, nasal discharge, and reduced activity. Veterinary assessment should be sought if respiratory symptoms are observed.
Fungal and Skin Infections: Persistently damp conditions can increase the risk of fungal or bacterial skin infections. Affected geckos may develop discoloured skin, lesions, or abnormal shedding. Maintaining a well-ventilated enclosure with only light, controlled misting helps reduce the risk of infection.
Metabolic Bone Disease (MBD): Metabolic Bone Disease is commonly associated with inadequate calcium supplementation, an incorrect calcium-to-phosphorus ratio, or nutritional deficiencies. Signs may include weakness, tremors, soft jawbones, limb deformities, and difficulty moving. A balanced diet and appropriate supplementation are essential for prevention.
Shedding Problems (Dysecdysis): Shedding difficulties can occur if humidity is insufficient or if the animal is in poor health. Retained skin is most often seen around the toes, tail, or eyes and can lead to circulation problems or infection if not addressed. Proper nutrition, hydration, and enclosure management help support normal shedding.
Parasites: Internal and external parasites may affect captive geckos, particularly newly acquired animals or those housed in unsanitary conditions. Signs can include weight loss, reduced appetite, diarrhoea, or poor body condition. Routine health monitoring and veterinary examinations can assist with early detection and treatment.
Routine Health Monitoring: Regular observation is important for the early detection of health problems. Keepers should monitor appetite, body condition, shedding, activity levels, and faecal output. Any significant changes in behaviour or appearance should be investigated promptly by a veterinarian experienced with reptiles.
Obesity: Obesity can develop in captive Thick-tailed Geckos when energy intake exceeds their requirements. Overfeeding, excessive supplementation, and limited opportunities for exercise can contribute to excessive weight gain. Signs may include a noticeably rounded body, fat deposits around the tail base and limbs, reduced activity, and difficulty moving normally. Maintaining an appropriate feeding schedule, offering suitably sized prey, and regularly monitoring body condition can help prevent obesity.
Health, Hygiene & Safety
Wash your hands before and after handling or working in its enclosure to prevent the spread of bacteria. Maintain a mostly dry, clean enclosure by spot-cleaning waste daily and removing uneaten insects promptly. Disinfect décor and hides periodically using reptile-safe products. Ensure cleaning tools and surfaces dry completely before returning them to the enclosure. Always wash hands before and after handling, and use feeding tongs to avoid accidental bites and maintain hygiene. Heat sources must be securely installed and never accessible to the gecko.
Record Keeping
It’s important to keep a log of feeding dates, prey type & supplements, shedding cycles, weight, enclosure cleaning, and any health concerns. Maintaining a detailed record log is crucial for monitoring its long-term health and wellbeing. By noting down the points above you can quickly spot any deviations from normal patterns – such as reduced appetite, irregular shedding, or weight loss – that may signal emerging health issues. Accurate records also help you fine-tune care routines, like adjusting feeding frequency or humidity levels, based on your pet’s individual needs. In addition, if veterinary care becomes necessary, having a detailed history of your pet’s care and any previous health concerns allows the veterinarian to diagnose and treat problems more effectively.
Holiday Care
When away from home, arrange for a responsible person – preferably another licensed reptile keeper – to look after your gecko. They must follow your feeding schedule, monitor temperatures, maintain humidity, and ensure the enclosure remains safe and clean. Provide clear written instructions and ensure your licence conditions allow temporary caretaking.
Transportation
Transport should always be calm and secure. Use a well-ventilated container with a stable substrate and a simple hide. Avoid extreme temperatures and sudden movements. Follow the NSW Code of Practice guidelines for safe reptile transport, including minimising stress and ensuring the enclosure is escape-proof during travel.
Compatibility with Other Animals
Thick-tailed Geckos should never be housed with other reptile species due to differing requirements and risk of aggression or disease. Multiple U. milii may be housed together if appropriately matched (one male with one or more females), but adult males should not share an enclosure. Keep all reptiles away from household pets such as cats or dogs, which pose injury risks.
Licensing
A Native Animal Keeper Licence is required to own a Thick-Tailed Gecko in NSW and must be obtained through Service NSW prior to purchase. All reptiles must be captive-bred and sourced from licensed breeders or registered pet stores. Wild collection and release of captive reptiles is illegal. Keepers must comply with the NSW Code of Practice for the Private Keeping of Reptiles, including housing, welfare and record-keeping requirements.
Helpful Reptile Keeping Links
NSW Code of Practice for the Private Keeping of Reptiles: https://www.environment.nsw.gov.au/publications/code-practice-private-keeping-reptiles
Understanding the licences: https://www.environment.nsw.gov.au/licences-and-permits/wildlife-licences/native-animals-as-pets/reptile-keeper-licences
Applying for a native animal keeper licence: https://www.service.nsw.gov.au/transaction/apply-for-a-native-animal-keeper-licence
Further Thick-Tailed Gecko Care Reading: https://reptilesmagazine.com/australian-barking-gecko-care-sheet/
