Ackie Monitor Care: Setup, Heat, Diet, and Daily Husbandry
I've kept ackie monitors (Varanus acanthurus) for years, and the single thing I'd tell a new keeper is this: they are tiny, hyperactive Australian desert predators, not display lizards. Get the heat and the dig depth right and they basically run themselves. Get those two things wrong and nothing else you do will save the animal. Everything below is built around that reality.
What an ackie monitor actually is
Ackies are dwarf monitors from the arid interior of Australia. Adults run roughly 20-28 inches total length, and about half of that is tail. They're intelligent, curious, and genuinely interactive in a way most lizards aren't: they hunt, dig, climb, and investigate constantly. That activity level is the whole point of keeping them, and it's also why a cramped or under-heated enclosure makes them miserable so fast.
They come in shades from brick red to earthy yellow over dark patterning, with a spiny tail they use for defense. They're docile for a monitor, but "docile" here means they tolerate keepers, not that they want to be cuddled.
Enclosure size and the substrate that matters more
For a single adult, treat 4 ft long x 2 ft wide x 2 ft tall as the floor, not the goal. More floor space is always better. Hatchlings can start smaller but will outgrow it quickly, so I'd rather just build the adult enclosure once.
The part new keepers underbuild is substrate depth. Ackies are obsessive burrowers, and burrows are where they sleep, hide, lay eggs, and find humidity. I run 8-12 inches of diggable substrate — a roughly 60-70% organic topsoil to 30-40% play sand mix holds a tunnel without collapsing. Skip gravel and bark chips; chunky loose material is the classic impaction risk.
On top of that, build a hardscape they can use:
Decor that earns its place
- Climbing and cover: cork bark, sturdy branches, stacked flat rocks (stacked safely so a dig can't topple them onto the animal).
- Hides at multiple temperatures: at least one warm, one cool, and ideally a slightly humid hide near a burrow.
- A basking platform: a thick flat rock or stacked slate directly under the heat that soaks up and holds warmth.
The goal is microclimates — hot and dry up top, cooler and slightly damp down in the burrows — so the animal can pick its own conditions.
Heat and lighting (this is the whole game)
Ackies need a basking spot that genuinely shocks new keepers. I run a basking surface temperature of 130-150°F, measured with an infrared temperature gun pointed at the basking rock — not air temp, not a stick-on dial. The cool end sits at 75-85°F. That steep gradient is what lets them digest, stay active, and self-regulate.
I get those temps with a tight cluster of halogen flood bulbs over the basking rock rather than a single weak fixture. A few rules I never break:
- Never put a heat element on the enclosure floor where the animal can press against it — burns.
- Run a 12-14 hour photoperiod to mimic their day length.
- Nighttime usually needs no heat unless the room gets genuinely cold; if it does, use a non-light ceramic emitter so you don't wreck their day/night cycle.
For UVB, use a high-output linear T5 bulb (often sold as 10-12%) mounted so the basking animal sits within the manufacturer's recommended distance, with no glass or plastic between bulb and lizard. Replace UVB bulbs every 6-12 months — output collapses long before the bulb visibly dies. UVB drives vitamin D3 synthesis, which drives calcium use, which prevents metabolic bone disease.
| Parameter | Target |
|---|---|
| Basking surface temp | 130-150°F |
| Cool end | 75-85°F |
| Ambient humidity | 40-60% (higher inside burrows) |
| Substrate depth | 8-12 in |
| Photoperiod | 12-14 hr light |
| Min. enclosure (1 adult) | 48 x 24 x 24 in |
Diet: insectivores, built around roaches
Ackies are insectivores. The bulk of the diet should be feeder insects — dubia or discoid roaches, crickets, and locusts are the staples I rotate. Roaches are my backbone because they're meaty, easy to gut-load, and don't smell or escape like crickets. I source feeders from All Angles Creatures' discoid roaches so I'm not breeding crashing colonies at home.
Two non-negotiables on feeders:
Gut-load and dust
- Gut-load insects for 24-48 hours before feeding so the bug is actually nutritious going in.
- Dust with calcium at most feedings. Nearly all feeder insects are phosphorus-heavy and calcium-poor, so the dusting is what keeps the calcium-to-phosphorus ratio right and prevents metabolic bone disease. I add a reptile multivitamin once or twice a week.
Pinky or fuzzy mice are a once-in-a-while fatty treat, not a staple — ackies obese out fast on rodents. Feed juveniles roughly daily to fuel growth and adults every 2-3 days, adjusting by body condition. A healthy ackie is lean and muscular, not a sausage.
Keep a shallow water dish available even though they rarely drink openly; most of their water comes from food and humid burrows.
Humidity, hydration, and shedding
Target 40-60% ambient humidity, with the real humidity living down in the burrows where damp substrate sits. That gradient — bone-dry basking surface, humid burrow — is exactly what they evolved with and what gives clean sheds. Keep one side of the deep substrate lightly damp, mist a humid hide if needed during a shed, and use a hygrometer rather than guessing.
Watch the failure modes at both extremes: chronically too wet invites respiratory infections and fungal/bacterial problems; chronically too dry causes stuck sheds (retained skin on toes and tail tips can constrict and cause damage). A humid hide or moss box solves most shedding trouble.
Reading health, and the daily routine
A thriving ackie is busy: basking, digging, patrolling, hunting with enthusiasm. The warning signs I act on fast are lethargy, refusing food, open-mouth or wheezy breathing, abnormal stool, unexplained swelling, or repeated stuck sheds. Any respiratory symptom or persistent appetite loss is a reptile-vet visit, not a wait-and-see.
My maintenance rhythm:
- Daily: spot-clean waste and uneaten feeders, refresh water, glance at temps and humidity.
- Weekly: sift the substrate for buried waste, wipe glass, check that branches/rocks are still stable.
- Monthly: deeper substrate refresh, inspect bulbs and timers, confirm basking temps haven't drifted.
When something goes wrong with an ackie, my troubleshooting order is almost always the same: check basking temp with the IR gun first (a too-cool spot causes appetite loss, lethargy, and hiding), then humidity for shed issues, then feeder size and handling stress for behavior. Heat is the answer to most ackie problems.
Handling and temperament
Let a new ackie settle for a couple of weeks before you handle it. Approach from the side rather than looming overhead (overhead = predator), move slowly, and fully support the body and tail. Keep early sessions short and let the animal's behavior set the pace — hissing, fleeing, or tail-whipping means stop. Hand-feeding builds positive association better than forced handling ever will. With consistency most ackies become genuinely tolerant and curious about their keeper.
If you want to go deeper on the feeder side of all this — especially keeping a clean, non-smelly roach colony going — my discoid roach keeping guide covers the staple feeder these monitors live on. You can also browse the rest of the exotic animal care library for related setups.
Related reading: keeping discoid roaches alive and the full exotic animal hub.