Giant prickly stick insects (Extatosoma tiaratum) are 5-6” long, nocturnal, herbivorous invertebrates found in the tropical forests of northern Australian and New Guinea. They are also known as spiny leaf insects, Macleay’s spectres, or Australian walking sticks.
Giant prickly stick insects have a thick body with lobed limbs, covered in small thorns. Males have fully-developed wings, while females’ wings are small and unusable. Giant prickly stick insects are usually light to medium brown in color, but they can also be dark brown or greenish. When threatened, this species will curl its abdomen to mimic a scorpion and hopefully deter a potential predator.
Giant prickly stick insects are popular pet invertebrates. Total lifespan for this species is typically around one year, with shorter at higher temperatures and longer and lower temperatures.
Minimum terrarium size for giant prickly stick insects
The widely-accepted minimum formula for housing stick insects is:
- Length = 2x length
- Width = 2x length
- Height = 3x length
Height is particularly important, as stick insects need vertical space in order to molt (shed their exoskeleton) and grow properly. Using the above formula, the enclosure for an adult-sized giant prickly stick insect should be at least 12”L x 12”W x 18”H and made of glass, plastic, or mesh.
Giant prickly stick insects generally get along well when housed together in groups. However, keep in mind that if you want to keep more of them in the same enclosure, you will need a bigger enclosure — particularly along the horizontal dimensions.
Do giant prickly stick insects need special lighting?
If your stick insect’s enclosure is placed in a room that receives ~12 hours/day of bright natural or artificial light, then additional lighting equipment is unnecessary. However, if your pet is being kept in a dark room or you wish to put live plants in the enclosure, then you will need additional lighting equipment such as a small white fluorescent or LED grow light around 6500K color temperature.
Best temperature for giant prickly stick insects
Giant prickly stick insects do best when they are kept between 70-80°F. This generally includes room temperature, so supplementary heating should not be required for keeping this species unless your room’s temperature falls outside of this range. The best way to keep track of the temperatures inside your giant prickly stick insect’s enclosure is with a digital thermometer placed in the middle of the enclosure.
If you do need supplementary heating to hit the right temps, the Zoo Med Nano Dome Lamp Fixture and 25w Zoo Med Nano Basking Spot bulb is a good combination to start with. Stick insects tend to hang upside-down from the top of their enclosure, so if you put the lamp directly on top of the mesh, there’s a good chance that your pet will get burned! Instead, suspend the lamp from a lamp stand.
Heat lamps should be turned off at night.
Best humidity levels for giant prickly stick insects
Providing the right amount of humidity is very important for making sure that your stick insect is able to molt properly and stays generally healthy. Too high and too low will both cause problems. For the giant prickly stick insect, their comfort zone is between 60-80% on average.
Lightly mist your pet’s enclosure at least once per day with a spray bottle to both increase the humidity and provide drinking water. Mesh enclosures will need misting more often than glass or plastic ones.
Keep track of the humidity in your pet’s enclosure with a digital hygrometer.
Best substrate for giant prickly stick insects
Your giant prickly stick insect terrarium should have at least 1-2” of substrate on the bottom to help maintain the humidity. Here are some moisture-friendly materials you can use:
- Zoo Med Creatures Eco Soil
- Zoo Med Creature Soil
- Zoo Med ReptiBark
- Eco Earth Plantation Soil
- Exo Terra Forest Bark
This substrate will need to be replaced weekly and the enclosure thoroughly rinsed out with hot water to maintain good hygiene.
How to decorate a giant prickly stick insect terrarium
In order to reduce stress, prolong your pet’s lifespan, and encourage natural behaviors, your giant prickly stick insect needs both objects to climb and hide behind in its enclosure. Here are some ideas of things you can use:
- cork logs/flats
- thin vines
- artificial foliage
Use hot glue to attach climbing objects to the sides and bottom of the enclosure at different angles for variety. However you arrange your enclosure, make sure to leave enough open space at the top for twice your pet’s height to use during molting.
What to feed to a giant prickly stick insect
Stick insects are herbivores, which means that they eat plants in order to get the nutrition that they need. Make sure a branch of fresh leaves is always available. You can stick this branch in a vase of water to keep the leaves fresh for longer!
Here are some options for leaves that are appropriate to feed to a giant prickly stick insect:
- Blackberry (older leaves only, no new leaves)
Oak leaves freeze well for use during winter, and blackberry leaves usually stay available through the winter as well. Romaine lettuce may be offered if you have nothing better on hand.
Never source leaves from garden centers or florists, as these are likely to be covered in chemicals that will harm your pet!
How to handle your giant prickly stick insect
As a general rule, invertebrates are “look-but-don’t-touch” pets: fun to watch, but not to be handled regularly. However, giant prickly stick insects generally tolerate handling better than most.
To pick up your pet, place a hand under its front legs, then use your other hand to coax it forward from behind. Be very gentle as you do this, as it’s easy to injure a stick insect. Let it step onto your hand of its own accord, and don’t force it!
*This care sheet contains only very basic information. Although it’s a good introduction, please further your research with high-quality sources. The more you know, the better you will be able to care for your pet!