Vietnamese Stick Insect
Species Description

The Vietnamese Stick Insect, scientifically known as Medauroidea extradentata, represents one of the most accessible and rewarding species for those entering the world of phasmid keeping. This species was formerly classified as Baculum extradentatum, and many scientific papers still reference the older nomenclature. The taxonomic revision to Medauroidea extradentata better reflects its phylogenetic relationships within the Phasmatidae family, though hobbyists and breeders often use both names interchangeably.

Commonly called the Annam Walking Stick after the historical Annam region of Vietnam, this species has earned its reputation as the premier beginner's stick insect. The common name Vietnamese Stick Insect directly references its native range in the tropical forests of Vietnam, where it inhabits dense vegetation and relies on exceptional camouflage to avoid predation. In the international pet trade and among stick insect enthusiasts, it may also be referred to simply as Vietnamese Walking Stick or Annam Stick Insect.

This species has been assigned Phasmid Study Group number PSG 4, indicating its long-standing presence in captive breeding programs and hobbyist collections. The PSG numbering system helps enthusiasts and breeders maintain accurate records and distinguish between similar-looking species. The Vietnamese Stick Insect's established position in the hobby, combined with its parthenogenetic reproduction allowing females to produce fertile eggs without males, has made it one of the most widely distributed stick insect species in captivity worldwide.

Vietnamese Stick Insects are masters of camouflage, possessing elongated, cylindrical bodies that perfectly mimic the twigs and small branches of their natural forest habitat. Adults typically reach four to five inches in body length, making them a medium-sized phasmid species that's substantial enough to observe easily yet manageable for beginners. When including their long front legs extended forward in their characteristic resting position, total length can reach eight to ten inches.

The coloration of Medauroidea extradentata changes throughout its life cycle and can vary between individuals. Freshly hatched nymphs emerge as light tan or beige, displaying smooth bodies regardless of their eventual adult appearance. During the early molts and adolescent stages, many individuals develop a vibrant green coloration, which can be quite striking against darker foliage. As they approach and reach adulthood, most Vietnamese Stick Insects transition to various shades of brown, ranging from light tan to dark chocolate brown, though some retain green coloration throughout their lives.

The head is oval-shaped with thread-like antennae that serve as important sensory organs. Their compound eyes are relatively small, and the species relies more heavily on tactile and chemical cues than vision. The mouthparts are specially adapted for herbivory, opening horizontally rather than vertically to efficiently process plant material. This unique jaw structure allows them to consume large quantities of foliage with remarkable efficiency.

Sexual dimorphism is present but subtle in this species. Females, which dominate captive populations due to parthenogenetic reproduction, are generally stockier with broader bodies and feature two small horn-like protrusions on top of their heads. Their bodies display small bumps along the thorax and abdomen, and their legs have tiny points that mimic thorns, enhancing their twig-like appearance. Males are considerably rarer in captivity, distinguished by longer antennae, thinner and smoother bodies, and the absence of head horns. Neither sex possesses wings, making them exclusively terrestrial climbers. The texture of adult exoskeletons often includes subtle ridges and patterns that perfectly replicate bark characteristics, completing their remarkable camouflage adaptation.

The Vietnamese Stick Insect exemplifies docility and calmness, making it one of the most handleable and beginner-friendly invertebrate species available in the pet trade. Their temperament is characterized by slow, deliberate movements and an almost complete lack of defensive behaviors beyond their remarkable camouflage. When disturbed, they typically respond by remaining perfectly still, sometimes dropping to the ground and playing dead until the threat passes. This thanatosis behavior is a passive defense mechanism that rarely escalates to more active responses.

These stick insects are primarily nocturnal, becoming most active during evening and nighttime hours when they feed and explore their surroundings. During the day, they adopt characteristic twig-like poses, often extending their front legs forward along their bodies to maximize their resemblance to plant material. They may remain in the same position for many hours, moving only when absolutely necessary. This sedentary daytime behavior is an energy-conservation strategy that also minimizes detection by visual predators.

When Vietnamese Stick Insects do move, they exhibit a fascinating swaying or wobbling motion that mimics twigs or leaves moving in a breeze. This behavior enhances their camouflage by making their movements appear natural rather than animal-like. The characteristic wobbly gait is more pronounced in younger individuals and becomes slightly less exaggerated as they mature. Observers often find this movement mesmerizing and it's one of the species' most endearing behavioral traits.

Social behavior is minimal in this species, as they're largely solitary by nature. However, they're extremely tolerant of conspecifics and can be housed in groups without aggression or territorial disputes. Multiple individuals often cluster on the same food plant, sometimes positioned so close together they appear to be a single plant stem. This clustering behavior may provide additional camouflage through the "safety in numbers" principle, though it's more likely simply a result of all individuals seeking the same optimal microhabitat conditions.

Reproduction in captivity is almost exclusively parthenogenetic, with females producing fertile eggs without mating. Adult females drop their eggs casually while feeding or resting, allowing them to fall to the substrate below. This reproductive strategy results in entirely female populations in most captive colonies. On rare occasions when males appear, they will court females through gentle antennal contact, though this is seldom observed in hobby collections. The lack of complex mating rituals simplifies breeding for hobbyists while ensuring reliable reproduction.

The species' gentle nature extends to handling interactions. When properly acclimated and approached calmly, Vietnamese Stick Insects will walk onto an extended hand or arm without hesitation. They move slowly and deliberately, making them easy to observe and safe for supervised interactions with children. However, their legs are fragile and can autotomize under stress, so all handling should be gentle and minimal. They show no tendency to bite, pinch, or display any defensive behaviors beyond occasional leg-dropping, making them exceptionally safe display animals.

Housing Vietnamese Stick Insects successfully requires attention to vertical space, ventilation, and appropriate environmental conditions, though their care remains straightforward compared to many exotic invertebrates. The enclosure must be at least three times the insect's body length in height to accommodate their molting needs, as they hang vertically during this vulnerable process. A minimum enclosure size of twelve by twelve by eighteen inches can house several adults comfortably, though larger enclosures provide more space for colony growth and behavioral observation.

Mesh or well-ventilated enclosures are strongly preferred for this species, as they provide the airflow necessary to prevent fungal and bacterial growth while maintaining appropriate humidity levels. Glass enclosures with screen tops can work but require more careful humidity management to prevent excessive moisture buildup. Many experienced keepers use purpose-built mesh cages or modify screen terrariums, as the fine mesh provides excellent climbing surfaces that stick insects can grip easily with their tarsal claws. Adequate ventilation is non-negotiable for preventing mold growth on food plants and maintaining overall enclosure health.

Substrate is optional for Vietnamese Stick Insects, as they spend virtually all their time on vertical surfaces and vegetation. However, a thin layer of paper towels, coconut fiber, or peat moss on the enclosure floor makes cleaning easier and can help maintain baseline humidity through occasional misting. Some keepers prefer no substrate, relying instead on easy-to-clean bare floors. The substrate choice should prioritize ease of maintenance and egg collection if breeding is intended, as females drop eggs randomly throughout the enclosure.

Temperature requirements are extremely forgiving, with the species thriving at typical room temperatures between sixty-eight and eighty-six degrees Fahrenheit. Most household environments fall within this range, eliminating the need for supplemental heating in most cases. If temperatures drop below the ideal range during winter months, a low-wattage heat mat placed on one side of the enclosure can provide gentle warmth. Avoid hot spots and dramatic temperature fluctuations, as these can stress the insects and complicate molting.

Humidity should be maintained at moderate levels around fifty to sixty percent, easily achieved through light misting every other day or daily during particularly dry periods. The goal is to provide drinking water on foliage surfaces without creating overly wet conditions that promote mold growth. Vietnamese Stick Insects drink water droplets from leaves, so regular misting serves the dual purpose of hydration and humidity maintenance. A small, shallow water dish is unnecessary and can pose a drowning hazard for nymphs.

Furnishing the enclosure requires little more than fresh food plants presented in a way that keeps them fresh and accessible. Branches of appropriate food plants can be placed in a water tube or small container with the opening sealed to prevent drowning. Replace food plants every few days or when they begin to wilt, ensuring a constant supply of fresh foliage. Some keepers add additional climbing branches or artificial plants to provide extra surface area, particularly in breeding colonies where multiple generations coexist.

Molting care is critical for this species' health and survival. Individuals preparing to molt will refuse food, display dulled coloration, and position themselves securely on vertical surfaces. During this time, absolutely do not disturb the insect, handle the enclosure roughly, or attempt any maintenance that might cause vibrations. Increase humidity slightly through gentle misting around, not directly on, the molting individual. After molting completes, the insect needs several hours to days for its new exoskeleton to harden fully before resuming normal activities. Remove any uneaten food during this period to prevent disturbance and reduce the risk of complications.

Vietnamese Stick Insects are obligate herbivores with straightforward dietary requirements that make them exceptionally easy to feed and maintain. Their natural diet consists entirely of fresh foliage from various broadleaf plants, and in captivity, they readily accept several commonly available plant species. This dietary flexibility is one of the primary reasons for their popularity among beginners, as suitable food sources are typically accessible year-round through gardens, wild foraging, or indoor cultivation.

Blackberry bramble (Rubus species) stands as the most universally accepted and recommended food plant for this species. The leaves are nutritious, readily available in many regions, and Vietnamese Stick Insects consume them enthusiastically. Both wild bramble and cultivated blackberry or raspberry leaves work equally well. Oak leaves (Quercus species) provide another excellent staple food, particularly red oak and white oak varieties. Rose leaves (Rosa species), hawthorn (Crataegus species), and red maple (Acer rubrum) are also accepted readily and can serve as primary or supplementary foods.

When collecting wild food plants, absolutely ensure they haven't been treated with pesticides, herbicides, or other chemicals. These substances are invariably fatal to stick insects even in minute quantities. Collect from areas you know are chemical-free, preferably deep within natural areas away from agricultural land and landscaping. If uncertain about a plant's safety, don't risk it. Many keepers cultivate their own bramble, oak, or rose plants specifically for feeding stick insects, guaranteeing pesticide-free foliage year-round.

Food presentation is simple but important for maintaining plant freshness and encouraging feeding. Place cut branches in a water tube or small container with the water access sealed using cotton, foam, or a tight-fitting lid with holes for stems. This prevents nymphs from drowning while keeping foliage fresh for several days. Replace food plants when they begin to wilt or dry, typically every three to five days depending on humidity and temperature. Some keepers prefer to provide potted plants, allowing insects to feed directly from living vegetation.

Feeding frequency essentially consists of maintaining a constant supply of fresh foliage. Vietnamese Stick Insects are continuous grazers that feed primarily at night but may nibble throughout the day. Unlike predatory invertebrates that require scheduled feeding, stick insects simply need access to fresh food at all times. Adults consume more than nymphs, and pregnant females may feed more heavily as they develop eggs. Monitor food consumption and adjust the amount provided to minimize waste while ensuring abundant availability.

Nymphs have the same dietary requirements as adults, accepting all the same food plants from the moment they hatch. Their smaller size means they consume less, but they require the same quality and variety. Newly hatched nymphs are particularly sensitive to food plant condition, so ensure extra-fresh foliage is available when eggs are hatching. They'll begin feeding within hours of hatching, climbing immediately to the nearest leaves.

No supplementation is necessary for Vietnamese Stick Insects when provided varied, high-quality food plants. They obtain all required nutrients from their herbivorous diet. Some advanced keepers occasionally dust food plants with calcium powder to support robust exoskeleton development, though this isn't essential for healthy growth and molting. The simplicity of their nutritional needs means successful feeding comes down to providing fresh, pesticide-free foliage from accepted plant species consistently.

Vietnamese Stick Insects are generally hardy and resilient when provided with appropriate care, making them among the most trouble-free invertebrate pets available. Their health issues are typically preventable through proper husbandry, emphasizing the importance of correct humidity, clean conditions, and pesticide-free food. Most problems arise from environmental factors rather than diseases, and early intervention usually results in successful recovery. Regular observation of feeding behavior, molting patterns, and activity levels helps keepers identify potential issues before they become serious.

The vast majority of health issues in Vietnamese Stick Insects are preventable through attentive husbandry and environmental management. These insects are remarkably forgiving compared to many exotic invertebrates, tolerating minor care mistakes and recovering well from most non-fatal problems. By focusing on the fundamentals of appropriate humidity, chemical-free food, and undisturbed molting conditions, keepers can expect their Vietnamese Stick Insects to thrive throughout their natural lifespan with minimal health complications.

Vietnamese Stick Insects are among the most handleable of all invertebrate species, making them exceptional choices for educational demonstrations and gentle interaction. Their calm temperament and slow movements allow for safe handling even by supervised children, though certain precautions must always be observed to protect these delicate creatures. Handling should be approached as an occasional enrichment activity rather than a regular practice, as these insects don't benefit from frequent human contact and can be stressed by excessive manipulation.

When handling is desired, allow the stick insect to walk onto your hand rather than grabbing or picking it up. Extend your hand in front of the insect and gently encourage it forward by touching its rear legs. Most individuals will climb readily onto an offered surface, moving at their characteristic slow pace. Once on your hand, remain still and allow the insect to explore at its own speed. They may walk up your arm or simply remain stationary, and both behaviors are normal.

The greatest risk during handling is falling, which can be fatal to stick insects due to their fragile exoskeletons and internal structure. Always handle over a soft surface such as a bed, couch, or padded table, and keep handling sessions low to the ground. Never allow stick insects to climb to high positions on your body where a fall could cause serious injury. Their legs can autotomize (deliberately detach) if grabbed or stressed, so never restrain the insect or attempt to prevent it from moving in its chosen direction.

Handling sessions should be brief, typically no more than five to ten minutes, to minimize stress. Signs of stress include rapid color changes, unusual stillness, leg autotomy, or attempting to climb away quickly. If you observe any stress indicators, immediately return the insect to its enclosure and allow it to settle. Some individuals tolerate handling better than others, and you should respect each insect's apparent comfort level rather than forcing interaction.

Daily care routines are minimal and straightforward, requiring only minutes per day under normal circumstances. Check food plants daily to ensure they remain fresh and abundant, replacing wilted foliage as needed. Mist the enclosure every other day or daily during dry periods, focusing on the foliage to provide drinking water. Remove any dead insects, molted exoskeletons, and excessive frass buildup weekly, though small amounts of frass don't require immediate removal and can actually contribute to enclosure humidity.

Complete enclosure cleanings are rarely necessary if spot-cleaning is performed regularly. Every few months, remove all inhabitants temporarily, discard old substrate if used, clean the enclosure with hot water (never soap or chemicals), allow it to dry completely, and set up fresh conditions. This deep cleaning prevents waste buildup and reduces the risk of bacterial or fungal issues, particularly in colonies that have been established for extended periods.

Vietnamese Stick Insects represent the gold standard for beginner invertebrate keeping, offering an ideal combination of easy care, fascinating behavior, and educational value. Their suitability for novices stems from their forgiving nature regarding minor husbandry mistakes, readily available food plants, and minimal equipment requirements. Unlike many exotic invertebrates that demand precise environmental conditions and specialized care, Vietnamese Stick Insects thrive under relatively simple conditions achievable in most homes without expensive equipment.

For families with children, this species provides exceptional opportunities for hands-on learning about insect biology, ecology, and life cycles. The short lifespan of five to seven months means children can observe complete development from egg to adult within months, maintaining engagement without requiring years of commitment. The gentle, handleable nature allows supervised interaction, fostering respect for living creatures and understanding of proper animal care. Watching eggs develop, nymphs hatch, and individuals grow through successive molts offers invaluable lessons in biology that textbooks cannot replicate.

Educators appreciate Vietnamese Stick Insects for classroom settings due to their safety, low maintenance needs, and remarkable demonstration of camouflage and adaptation. A single classroom colony can produce enough eggs to provide every student with their own to observe hatching, creating personal investment in the learning process. The species' docility allows students to handle specimens during demonstrations, making abstract concepts tangible and memorable. Their modest space requirements mean even small classrooms can house healthy colonies without dedicating significant room to enclosures.

However, potential keepers should understand several important considerations before acquiring this species. The short lifespan, while useful for observing complete life cycles quickly, means frequent turnover in populations. Those seeking long-term individual bonds with their pets might find the brief lifespan disappointing. The parthenogenetic reproduction means colonies continuously produce eggs, potentially overwhelming keepers who don't plan for population control. Eggs can be frozen humanely if population management becomes necessary, but this consideration should factor into the decision to keep breeding colonies.

The species' exclusively herbivorous diet requires reliable access to pesticide-free food plants year-round. Those without gardens or wild collection areas may need to cultivate food plants indoors, which demands some planning and space. Additionally, Vietnamese Stick Insects are escape artists capable of squeezing through surprisingly small gaps, so enclosure security is essential, particularly in homes with other pets that might harm escapees.

Overall, Vietnamese Stick Insects serve beautifully as starter species for those interested in invertebrate keeping, educational tools for classrooms and families, and low-maintenance display animals for anyone fascinated by insect behavior and biology. Their combination of accessibility, interesting behaviors, and straightforward care makes them nearly impossible to match as beginner-friendly invertebrates, explaining their enduring popularity across decades of hobby keeping.