Book Extract: Invisible Housemates

The humble house lizard, also known as a gecko, has long been a silent observer of human life, taking up residence in the nooks and crannies of our homes. In its book, the house gecko probably considers himself a mini superhero—guzzling unwanted flies and mosquitoes, providing humankind a service by keeping insect populations in check. These tiny reptiles, often no bigger than your palm, have a knack for blending into their surroundings and creeping up on us unsuspecting humans. They are masters of camouflage and can seemingly materialize out of thin air, reducing even grown adults to fits of screams. Their quick movements, darting between walls and ceilings, add an unexpected element to daily life. 

For some reason, house geckos seem to have a deep appreciation for the bathroom. One could mistakenly think that they come as an optional feature in this important real-estate space. You could be reaching for a towel or singing a ballad in the shower, when the sudden appearance of a gecko makes you perform an impromptu dance, which involves a frenetic leap away from the wall followed by a graceful pirouette as you attempt to regain your composure.

Perhaps the gecko sings its own ballad, unknown to us humans. After all, they’re the only reptiles known to possess a real voice. Their distinctive shrill sound ‘chuck, chuck, chuck’, has led to onomatopoeic names in Southeast Asian languages, such as ‘toki’ and ‘chichak’. In Hindi, they go by ‘chipkali’, ‘tiktiki’, and ‘chikchiki’, while their association with leprosy (korha in Punjabi) has given rise to the name ‘korkhili’.

They have a penchant for drama, and their performances are nothing short of spectacular. Watch a gecko stalk and capture a wayward fly or playfully chase its own reflection on a glass surface, and you will know what I mean. Their pursuit of small insects, locked in epic battles with mosquitoes, flies, and moths is like watching a David Attenborough documentary, complete with the suspenseful chase scenes and the inevitable ‘gotcha!’ moment. 

If you want to up the ante on drama and entertainment, get a dog and you’ll have a ringside seat to a Nat Geo show. My dog thinks that geckos are her best friends. Every time she sees one, she wants to play ‘doctor-doctor’ with the reptile. She tries to do a physical investigation of its health, first with her paw, and then sniffs it to check its vitals before scooping it up in her mouth to give it a full body scan. Unfortunately, the gecko doesn’t quite get the game, and its weak heart traumatized by the ordeal of being in a dog’s mouth, goes into cardiac arrest. I have had to discard many unsuspecting geckos that found themselves a drooly grave. 

While I believe in sharing space with these creatures, I expect them to respect boundaries and not push my hospitality. One day, I walked into my bedroom to find a baby lizard luxuriously resting on my bed. I froze mid-step, then darted with a newspaper and picked up the opportunistic guest and threw it into the garden. Years of composure was lost and for days, I had nightmares of lizards crawling up my bed and on my hand. 

Despite their repulsiveness, lizards have found a special place in the hearts of reptile enthusiasts as pets, particularly in the United States. They are often less demanding and less expensive than traditional pets like dogs or cats, and have become beloved members of many households. Yet, even these low-maintenance companions require a bit of care, from providing food, water, and scheduling regular check-ups to getting the right enclosure with enough room for them to climb and hide and a substrate to maintain humidity. The bearded dragon, a lizard that looks like a miniature dragon, is a popular pet due to its gentle and curious nature. Named for the tiny spines on its chin and neck that look like a beard, this lizard, as long as your forearm, can be easily tamed and loves to be taken for a walk or to play with other animals. 

Lizards have also found their way into pop culture. The Star Trek universe features many lizard men, such as Jem’Hadar, Reptilian Xindi, and the Gorn. The Gorn were a high-tech race. Equipped with starships and advanced knowledge, they viewed other species with contempt and aggression. In stark contrast, the Jem’Hadar were mindless and fuelled by drug addiction. Sharing the Gorn’s hostile nature, the Reptilian Xindi were territorial predators, driven by instinct and a thirst for domination. 

Fans of Doctor Who and its eponymous, eccentric but lovable time traveller would be familiar with the Silurians, a subterranean race of lizard men. These prehistoric but scientifically advanced reptile humanoids went into self-induced hibernation to survive a catastrophic Earth event. There is even a Silurian hypothesis written in 2018 by two American scientists suggesting the presence of an ancient species more advanced than humans. Perhaps this hypothesis and Dr Who’s Silurian were inspired by the 7,000-year-old figurines with lizard-like faces supposedly worshipped by the Ubaids in Mesopotamia. 

Then there’s Rango, a flamboyant chameleon with delusions of grandeur. Voiced by the inimitable Johnny Depp, Rango is a quintessential anti-hero. Thrown into the dusty, lawless town of Dirt, this accidental sheriff becomes an unlikely saviour. With a flair for the dramatic and a penchant for improvisation, Rango’s journey from pampered house pet to fearless lawman is a comical yet captivating ride.

No lizard, real or fictional, has quite managed to eclipse the towering, terrifying shadow of Godzilla. Since his incendiary debut in 1954, this behemoth has reigned supreme as the undisputed king of monsters. Six decades later, Godzilla’s roar still echoes through the hearts of fans worldwide, a testament to his enduring power and cultural impact.

All said and done, lizards have long been an intriguing part of human cohabitation. These small creatures are found in many homes around the world, but they are also shrouded in numerous myths. In the world of gecko superstitions, even the minutiae hold significance, and these charming reptiles have carved out a unique place in our collective imagination. 

In many parts of Southeast Asia, house geckos are also thought to protect homes from evil spirits and malevolent forces. It is said that they act as sentinels, warding off negative energy and deterring evil entities. Some people even welcome house lizards into their homes, viewing them as benevolent spirits in reptilian form. 

As Chithra Madhavan noted in a New Indian Express article on 26 June 2023, Shiva is supposed to have appeared as a monitor lizard in Magaral, Tamil Nadu. The temple has a sculpture of the monitor lizard on the gopuram, the conical roof, and the deity is referred to as Udumbeshwarar (after the Tamil word ‘udumbu’ for monitor lizard). 

In the Varadharaja Perumal temple at Kanchipuram in Tamil Nadu, silver and gold lizards are embedded on the ceiling of a small chamber in this temple. Thousands of devotees flock to touch these metallic lizards as it is believed that doing so will remove all sins and cure illnesses. While it’s one thing to touch metallic lizards and wipe your life slate clean, it’s completely different if a lizard touches you, or heavens forbid, one falls on you. Some Hindus believe that if a gecko falls on a person, illness is sure to follow unless they cleanse themselves in the sacred waters of the Ganges. In Uttar Pradesh, the omen can mean good or bad depending on which shoulder the gecko lands.

In a journal article, ‘The Folklore of Geckos: Ethnographic Data from South and West Asia’, the author Jurgen W. Frembgen documents several tales intertwined with these creatures. In Uttar Pradesh, there is a saying, ‘he can keep secrets like a gecko’ (chipkali ki tarah muh band rakta hai). On the other hand, Bengalis believe that when a gecko calls while someone is speaking, their words are true, or the events described are bound to happen. In parts of north India, the sound of a gecko’s call can herald evil unless it’s mimicked. In the region between north India and Afghanistan, contact with a gecko or its excreta is thought to cause the skin disease, leukoderma. Hindu mythology even weaves a tale where Lord Shiva prepared a unique poison for the gecko, as the gecko was the last to arrive and he ran out of poison while dispensing it to all living creatures2. Of course, house geckos have been proven to be non-poisonous and harmless to humans. That said, they carry various types of pathogens in their bodies, which can cause food poisoning if one consumes food contaminated with a gecko or its excreta. 

Despite these tales and superstitions, the belief that geckos should not be killed is widespread. In north India, it is said that a housewife’s meal might lose its taste if she kills one. In Punjab, geckos should not be killed, but taken out of the house with a stick tied with a cloth, to prevent the house from being cursed. In UP, a house with many geckos is seen as prosperous, and harming a gecko may hinder fertility for the women in the house. In fact, across cultures, geckos symbolize fertility2. This makes one wonder if there’s a story somewhere which foretells that if a baby lizard falls on someone, a baby will be born in that house in the next nine months! 

The Tamil Panchangam (traditional calendars with Hindu festival days) has even got a page devoted to lizard predictions, divided into two parts. The first part predicts events based on the number of calls, and the direction from which the lizard calls. The second part of the Tamil Panchangam portends good or evil based on which part of the body the lizard falls. If it falls on one’s head it portends sorrow or loss. If it falls on the forehead or the right arm, it means wealth2. All this calling and falling though brings to mind a Bollywood film hero who, after falling for a girl, has a calling to break into song and dance. 

We Indians are not the only ones to have omens and folklore about geckos. For Native American tribes, lizards are said to symbolize survival and healing. In some tribes, children are given amulets (good luck charms) in the shape of lizards for protection and strength. As for Arab countries, their beliefs take an even more unexpected turn, with gecko parts being used for unconventional purposes. Gecko blood and urine are believed to be effective when applied for certain medical conditions2. 

In Christianity, lizards are generally looked upon as evil due to the story of Adam and Eve, where a snake (related to lizards) convinced Eve to eat the forbidden fruit. However, lizards are mentioned in the Bible as one of four things that are wise despite their small size. The passage states that lizards are wise because they can get into the king’s palace undetected 2. So the next time you are overcome with a feeling to shoo away these humble creatures, remember that they have the blessings of the Lord himself and perhaps would be the first to be welcomed on the next Noah’s ark, whenever that may be. The same cannot be said of us humans. 

Abhijeet Christopher Loreng writes in a Times Now article on 25 April 2023, that in Celtic culture, there’s a story of a night goddess called Evaki who stole sleep from the lizard’s eyes and gifted this sleep to all other creatures in the land. Therefore, the lizard is thought of as a creature that symbolizes restlessness. On the other hand, newly married Celts listen for a gecko’s call on their wedding night to solidify their new relationship and to bring them luck. 

Whether they are heralded as protectors of the home, or feared as omens of bad luck, or even mystical beings, house lizards have woven their way into the cultural fabric of many societies. They are creatures that embody the complex interplay between culture, mythology, and the natural world, revealing the intricate web of human-animal relationships. In fact, lizards have fascinated humans to the extent that they have spurred world-wide quests to reveal their secrets. Many scientists have taken up the study of lizards, called saurology, from the Greek word, ‘sauros’ meaning lizards.

Dr Aaron Bauer, an American scientist, has made the study of lizards both his passion and profession. He has trekked across continents in search of lizards and has identified more than 230 reptile species, the most any living scientist has discovered. Among his many discoveries is a new and extinct species of lizard, trapped in amber 110 million years ago. Conferred with the moniker, ‘lizard king’, he even has a lizard species named after him, the Gekko aaronbaueri. 

James Stroud at the Georgia Institute of Technology, conducted a fascinating long-term study of lizards to examine how evolution unfolds in a community. His research was so elegantly simple, even a curious school kid could replicate it in their backyard. He collected four different species of Anolis lizards (anoles) on a small island in Florida, measured each lizard’s head, legs, feet, weight, and even the stickiness of their toes. Each one was tagged and released in the same area. He collected groups of lizards over ten years, with each group spanning two-and-a-half years, representing approximately two to three generations. Every six months, he caught the same lizards and measured them again. Some years, lizards with longer legs would survive better, and other years, lizards with shorter legs fared better. Other times, there was no clear pattern at all. His research showed that contrary to conventional knowledge of constant change, species can appear static while still undergoing intricate evolutionary adjustments beneath the surface. 

Maria Thaker, a scientist at the Indian Institute of Science, Bengaluru, studies how lizards communicate with each other, and learn to adapt to fast-changing urban environments. Her lizard of interest is the Indian rock agama, a lizard commonly found basking on rocky hills in south India, and on stony compound walls of yesteryear Bengaluru homes. Maria’s research found that the males are a living canvas, changing hues across their bodies in the blink of an eye, differently during courtship and during aggressive interactions. Most lizards get their grey or brown colours soon after they hatch. However, the vibrant yellow and red of rock agamas develop as they grow, extracting the colours from their diet of caterpillars, wasps and bees. Like most males of the animal kingdom, only the adult male rock agamas are flamboyant. The reason: to attract a mate. When courting a female, the male’s dorsal stripe shifts from sunny yellow to fiery orange or red, but turns an even brighter yellow when confronted by a rival male. Meanwhile, their lateral stripes dramatically darken to black for potential mates, a colour that is particularly attractive to females. On encountering a rival male, the black changes to yellow or red—a warning sign. The colour change is more intense and rapid in male-male encounters. Sadly, with Bengaluru’s changing landscape as individual houses gave way to high-rise buildings, these lizards have all but vanished from the city. 

Other scientists like Neil Losin and Nate Dappen believe that lizards, with their versatility and ability to occupy every possible habitat, are the key to understanding the past, present and future of life on Earth. In their 2017 documentary, Laws of Lizards, the two scientists embark on a year-long journey chasing lizards to understand their history and that of life itself. 

The history of lizards, in fact, starts from the time dinosaurs walked the earth. The very name ‘Dinosauria’ means ‘terrible lizards’. But as we dig deeper into the evolutionary archives, a fascinating truth begins to emerge. While lizards and dinosaurs share an ancestry that stretches back millions of years, and have common genetic traits, they are only distantly related. 

Dinosaurs, the colossal creatures, once roamed the Earth between 250 to sixty-five million years ago during the Mesozoic era, aptly known as the age of reptiles. At the end of the Mesozoic era, all of the dinosaurs went extinct. Other reptiles survived, however, and they eventually gave rise to modern reptiles. The saga of reptilian evolution has many chapters. Long before lizards scampered into existence, the stage was set by their predecessors. The first modern reptiles to chart their own course in the evolutionary journey were Lepidosauria, the forerunners of lizards and snakes (belonging to the order Squamata) and tuatara, the only surviving member of the order Rhynchocephalia. 

Squamata came into existence approximately 250 million years ago. Within the Squamata order, an astounding diversity of life has flourished. According to the reptile-database.org website, as of September 2024, there are around 4,000 species of snakes and 7,000 species of lizards, with more species being discovered every year. The lizard species commonly known include geckos, iguanas, worm lizards, monitor lizards, skinks and Komodo dragons.

Most lizards are small creatures, measuring a few inches in length, except for the Komodo dragon, that stands the largest with a length of three meters. Two lizard species, Sphaerodactylus ariasae, discovered in Beata in the West Indies, and Sphaerodactylus parthenopion, found in the British Virgin Islands, hold the record for being the smallest of all known species of reptiles, birds and mammals. With a mere length of 1.6 centimetres, they are smaller than a cockroach. 

Apart from geckos, India is home to a fascinating array of lizard species, each with unique adaptations and behaviours. India is home to four monitor lizards: the Bengal monitor, the Asian water monitor, the yellow monitor, and the desert monitor. These solitary lizards, that look like miniature dragons, are unfortunately hunted and trafficked for their meat and body parts, including their genitals, which are sold as the Hatha Jodi plant, which is falsely believed to bring good luck.

The Indian spiny-tailed lizard is India’s only herbivorous lizard found in the arid and semi-arid regions of western India. This solitary lizard burrows underground, coming out only to forage for food or occasionally to sun-bask. Locally known as sanda, the fat in their broad tails is believed to be a cure for male impotence and hence they are frequently hunted. The extracted sanda oil is sold not only in India but also exported to countries in the Middle East. As a result, their populations have dwindled drastically, and these reptiles are now listed as ‘vulnerable’ on the International Union for Conservation of Nature (IUCN) red list.

Flying lizards, found mainly in the hilly forests of India, are nature’s gliders, using flaps of skin to glide between trees. Fanthroated lizards are known for their vibrant throat fans, which they use to attract females during mating season. There are fifteen species found primarily in dry shrublands and coastal areas. Chameleons are renowned for their colour-changing abilities and lightningfast tongues, which can shoot out to capture prey in the blink of an eye. Garden lizards, or calotes, are adept at blending into their surroundings. Males, in particular, sport a striking red head and crest during mating season. Rock agamas are well-adapted to life in rocky habitats, where they blend seamlessly with their surroundings. Skinks, with their sleek, shiny scales, are commonly found in gardens and open fields. 

Lizards boast of a unique chemosensory system that lets them smell by tasting the air around them. The chemosensory organ, called Jacobson’s organ, which normally resides in the nose in most other reptiles and mammals, including us humans, is nestled within the mouths of lizards and snakes. Smells and chemicals picked up by the tongue are transferred into the Jacobson’s organ in the roof of the mouth, where the signal is processed. This evolutionary adaptation has enabled them to detect and discriminate prey chemically, giving them an uncanny advantage. But that’s not all—lizards, in their quest for survival, have perfected the art of self-renewal. Every year, without fail, they shed their skins. This process, a kind of natural rebirth, ensures their vitality in a world filled with ever-changing challenges.

Just like humans, most lizards possess eyelids to keep their eyes clean and safe. But some, such as geckos, are unique. They can’t blink, relying instead on a transparent membrane to protect their eyes from dust and intense sunlight. To maintain their vision, geckos employ their tongues to gently wipe away any debris. Many lizards, like iguanas, are blessed with colour vision. Their colourful bodies serve as a visual language, allowing them to communicate with one another and distinguish between males and females.

The common house gecko (Hemidactylus frenatus) belongs to the lizard family Gekkonidae, which has around 2,000 species. The house gecko was originally a tree-dweller and has now successfully adapted to buildings and urban environments. These little reptiles boast a colour palette that spans from beige and grey to light brown and even iridescent greenish hues. Measuring in at around 11 to 15 centimetres in length, these geckos are covered in protective scales. Males often outweigh their female counterparts, flaunting wider jaws.

The house gecko’s love story knows no bounds. They reproduce sexually, with breeding occurring year-round in tropical climates and seasonally in cooler regions. A unique ability of the female gecko is to store sperm for up to a year post-mating. This helps increase their reproductive success, especially when it comes to embarking on journeys to new habitats or when suitable males are scarce15. 

Their mating season typically occurs between March and July, and the female lays a clutch of two eggs between April and August. 

The female’s translucent belly unveils the magic happening inside. The eggs are hard-shelled, unlike those of other reptiles which are soft and can dehydrate under dry conditions. The house gecko lays its eggs in crevices or other hard-to-reach places to protect against predators. As these eggs incubate over a period of forty-five days to two months, the female’s body heat serves as a nurturing cradle. 

And let’s not forget their young, for they are as self-reliant as their parents. With caruncle-shaped teeth, they skilfully crack their way out of the egg and into the world. After a brief period of absorbing the yolk’s goodness, the hatchlings, not much bigger than a fingertip, attain maturity within a short period of six months, and are ready to embark on their own journeys. 

The house gecko is ectothermic, which means that they can regulate their body temperature based on the environment. They seek out warm places when it’s cold and hide in crevices when it’s warm. They regulate their body temperature during the day and forage for food at night. The gecko will eat any insect they can catch and swallow with their prehensile tongue. They are most active around midnight, so if you are heading to the kitchen for a midnight snack, make sure you don’t intrude upon the gecko savouring their meal.

House geckos are native to Asia and Southeast Asia, and ideally prefer tropical and sub-tropical environments. But they can endure any environment, even harsh climates and deep waters. They also have a high tolerance to light. House geckos are quite territorial. When confronting other members of the same species, they can become violent and are known to be more aggressive than other gecko species. Their aggressive nature and ability to adapt has led to their widespread distribution across the globe and caused the decline of native species of geckos in America and the Pacific. 

But what truly sets geckos apart is their remarkable resilience in the face of adversity. Most possess fracture planes in the bones of their tail, enabling them to shed their tails when cornered by predators. Some can even cast off their tails voluntarily, demonstrating the incredible ways nature has equipped them to escape danger. This ability of the lizard to shed its tail in danger has inspired scientists to design a building resistant to collapse. With extreme weather events such as floods, landslides, earthquakes, or even design errors, buildings can collapse causing loss of property and lives. The new design arrests the collapse from spreading and prevents the building from collapsing. 

After the lizard loses its tail, it can regenerate another one rapidly, although the regrown tail does not have the usual bony vertebrae but rather a cartilaginous rod. Scientists at the University of Southern California are studying the science behind this process where lizards regenerate cartilage as a possible therapeutic treatment for millions of people suffering from osteoarthritis. 

Lizards also use their tails to control the orientation of their bodies when leaping through the air. By deftly adjusting their tail’s angle mid-leap, these agile reptiles can effortlessly correct their body orientation and land gracefully on their feet. Inspired by this natural marvel, scientists have engineered Tailbot, a tiny robotic marvel equipped with a motorized tail and advanced sensors. By mimicking the lizard’s tail movements, Tailbot achieves astonishingly precise landings, transforming a simple leap into a feat of robotic engineering.

Despite their adaptations and resilience, a house gecko’s lifespan is generally no longer than three to five years. But they can live anywhere up to twenty years in captivity or while being kept as pets. Climate change and global warming is expected to hit these reptiles pretty hard as they are not equipped to regulate their body temperatures to high heat. It is estimated that one-fifth of lizard species globally will go extinct by 2080 due to global warming. Lizards are also impacted by the illegal wildlife trade. The flying gecko, Gekko kuhli, is targeted both for the illegal pet trade and consumption. The monitor lizard, Indian spiny-tailed lizard and many other species are illegally traded for traditional medicinal purposes. Tokay geckos, one of the largest living gecko species, are in demand for consumption in wine or whisky to increase strength and vigour. 

The gecko’s tale is one of survival and adaptability. They remind us that even in the face of immense change, life finds a way to endure and thrive. No wonder Dominique Lapierre in his book on Calcutta, City of Joy, wrote that the cry of a gecko is regarded an omen for long life. These creatures are living relics, survivors of a bygone era, and their ongoing journey through time is a testament to the wonders of evolution. They keep us on our toes, reminding us that, in the grand scheme of things, we’re just guests in their world.

**********

Deepa Padmanaban, Invisible Housemates: The Secret Lives of monkeys, geckos, pigeons and other creatures we live with.. ,‎ Harper Collins India, 2025. Pb. Pp.320

No man is an island, but even if he were, there would be no escaping the many quieter beings that share space with him. From spiders weaving webs in the corners of our living rooms, to the gecko waiting for careless moths outside our windows, no person is ever alone, and this should be reason enough to uncover the secrets of the animals around us. To get to know our invisible housemates.

This book not only brings you folk stories, myths and details of local and cultural beliefs about these animals, but also information about the roles they play in shaping modern pop-culture and scientific inquiry – leading to breakthroughs that can save lives.

Deepa Padmanaban is a writer, journalist, and former scientist. She grew up in Mumbai, lived and worked in Germany and USA, and currently lives in Bengaluru.