Thick-Tailed Gecko Care Guide - Birdsville Bird Shop, Sydney

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 an average lifespan of 8 to 10 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.

Basic Information

The Thick-tailed Gecko is a small to medium-sized, ground-dwelling Australian native found across arid grasslands, rocky outcrops 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 8–10 years with proper care.

Essential Supplies

Carry Enclosure

A sturdy, escape proof and well-ventilated carry enclosure is mandatory for all repltiles leaving Birdsville. Carry enclosures are essential for any reptile transportation.

Secure Enclosure

A low, wide enclosure (45–60 cm long) suits this terrestrial gecko best. Smooth Knob-Tails are active ground hunters, so floor space is more important than height. The lid must be secure, well-ventilated and escape-proof, as these geckos are surprisingly strong and agile for their size.

Substrate

Use clean fine sand, a sand-soil blend, or a commercial desert reptile substrate. This species thrives on dry, loose ground that allows natural burrowing and comfortable movement. Avoid substrates that clump when wet, become dusty, or contain sharp particles. It’s important to spot-clean daily to remove waste or shed insect parts, fully replace substrate every 4–6 weeks depending on cleanliness, ensure the substrate remains dry as moisture encourages fungal growth and lastly, to 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 to 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

Knob-Tails require a warm zone maintained precisely using a thermostat-controlled heat source. Many keepers prefer under-tank heat mats, although overhead ceramic heat emitters also work well.
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 to 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 desert 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, to 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.

UVB Lighting

High-quality UVB lighting (10.0 output or higher) is essential to support vitamin D synthesis and calcium absorption, helping prevent metabolic bone disease.

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 to rinse cleaned décor thoroughly and allow to dry completely.

Housing

A single adult requires approximately a 45–60 cm long enclosure with more floor space than height. Because these geckos live in sandy plains, the environment should remain mostly open with secure hides and areas of cover rather than dense vegetation. 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. Avoid overly moist décor as this species thrives in dry, well-ventilated enclosures.

Environment

Smooth Knob-tailed Geckos are an arid-zone species and require a warm, dry enclosure that allows them to regulate their body temperature. A thermal gradient should be provided, with the warm end maintained at approximately 32–35°C and the cooler end between 22–26°C. Night-time temperatures may decrease naturally but should remain within a safe range and the enclosure should not become cold or damp. Heating devices should be regulated by an appropriate thermostat to prevent overheating and reduce the risk of thermal injury. Suitable heat sources may include heat mats, heat cables, radiant heat panels, or ceramic heat emitters positioned to create a temperature gradient throughout the enclosure. Relative humidity should generally remain low, reflecting the species’ natural habitat. Adequate ventilation is important to minimise excessive moisture build-up and reduce the risk of respiratory or fungal disease. A natural day and night light cycle of approximately 10–12 hours of light per day should be provided. While UVB lighting is not considered essential for this nocturnal species, low-level UVB may be provided as part of a balanced husbandry program and may assist with vitamin D synthesis and calcium metabolism.

Diet & Feeding

Smooth Knob-tailed Geckos are insectivorous and should be offered a varied diet of appropriately sized live insects. Suitable feeder insects include crickets, wood roaches, mealworms, silkworms, black soldier fly larvae, and other commercially available feeder species. Prey items should be no larger than the width of the gecko’s head. Juveniles generally require more frequent feeding than adults due to their growth requirements. Feeder insects should be well nourished 24 – 48 hours before being offered and supplemented with gut-load, calcium and vitamins as required to support normal growth, bone development, and overall health. 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

Handling should be kept to a minimum and only undertaken when necessary for husbandry, enclosure maintenance, transport, or health assessments. Excessive handling can cause stress and may increase the risk of injury. Like many gecko species, Smooth Knob-tailed Geckos are capable of tail dropping as a defence mechanism. Although the tail can regenerate, this process requires significant energy and may temporarily affect the animal’s health and condition. Enclosures should provide multiple secure hiding places and opportunities to exhibit natural behaviours, including sheltering, thermoregulating, and foraging. Environmental conditions should be managed to minimise stress and support the species’ behavioural and physiological needs. Observation rather than frequent handling is the preferred method of monitoring the animal’s health and wellbeing.

Common Health Concerns

Smooth Knob-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

Smooth Knob-tailed Geckos can become dehydrated if they do not have access to fresh drinking water. 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 dry enclosure with good ventilation 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)

Although uncommon in this arid-adapted species, shedding difficulties can occur if environmental conditions are unsuitable 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 Smooth Knob-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. Obesity may increase the risk of reproductive, metabolic, and general health problems. 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 dry, clean enclosure by spot-cleaning waste daily and removing uneaten insects promptly. Disinfect décor and hides periodically using reptile-safe products. Because this species is sensitive to dampness, ensure that 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
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 pets individual needs. In addition, if veterinary care becomes necessary, having a detailed history of your pets 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, 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.