Lizards

Lizards are found around the world. They are harmless. They belong to the phylum Chordate and the class Reptilia. There are about 5000 species of lizards. Their size varies from few centimeters to few meters in length. Lizards live in deserts, forests, rocky areas, on ground and on trees.

Lizards have four legs, clawed feet, and a long tail. Their skin is scaly and they are cold blooded animals. There is an opening for ears in the head region.

Lizards are nocturnal animals. They are active in the night hunting for their food. They spend their day basking in the sun to warm them up. They recharge their life’s battery during the day this way to hunt during the night. They sleep during winter and on warm days they come out to hunt their prey.

Lizards feed on bugs, spiders, flies. They also feed on small plants, small animals depending on their size.

Most lizards use their eyes for locating their prey. Some of the species of Lizards use the sense of smell. Mouth of the Lizards has jaws, and teeth. Their teeth are bounded on the roof of their mouth.  Lizards have a long projectile tongue with the help of which they can catch their prey without getting close to their prey.

Lizards are more visually oriented reptiles. Lizards rely on vision for their survival. Their eyes are well developed.Their eyes can recognize colors. They can see colour better than human beings. They use colour to communicate and make decisions, and they can even see colours in very dim light.

They have a long tail. But the tail is weak. The tail is used as a weapon to escape from their enemies.  Their tail will break and the lizards will run away during the encounter with their enemies. They can regenerate or regrow their tail. Fat is stored in their tail.

Lizards can run, climb and cling and crawl on the walls, ground, and floor even on trees.  Their tail helps them to balance in these movements. They can stay on vertical or horizontal walls for a long time without falling. We often see the lizards walking on the ceilings without falling, defying gravity. Lizards can even move freely on glass surface without skidding. How is this possible?

Lizards have pads on their toes.  Therefore the toes are bulgy and pulpy.  The bulging toes are covered with tiny microscopic hairs called setae. Each setae splits into smaller bristles called spatulae.  These tiny hairs get close to the corners of walls and ceilings with the help of Van der Waal’s forces. That is electrons from the spatulae and the electrons of the walls interact with each other in order to create electromagnetic attraction.

Toes of the Lizard acquire a large surface area compared to its size because of setae and spatulae. The spatulae exerts week Van der Waal’s force on the wall and ceiling surface to adhere to them. Larger the surface area created at the toes greater the advantage. Attraction caused by the Van Der Waal’s force is greater.

Lizards are also light in weight. The larger number of spatulae and the weak Van der Waal’s force help lizards to adhere to almost everything.

The structure Setae do not stand straight at 90 degrees but branch out obliquely. They are also ultra-flexible. When the lizards jump from one surface to another surface, the toe hairs absorb huge amount of energy and redirect it. The flexibility and the stretchiness of the Setae help the lizards to walk across any surface at any angle.

If the surface is having moisture, the adhering capacity is reduced and the lizard will slide. If the Setae are too long and too flexible they get tangled and the lizard will fall off.

Lizards are also able to balance the force of gravity by applying their own force on the walls and ceilings. They can press and slide their feet towards their body and drag their feet across surfaces without falling. Force of friction also plays a vital role in their locomotion.

Scientists are researching the structure of Spatulae, the tiny hair like structure present in the toes of Lizards. According to them, each spatulae is 200 nanometre in length and width. The Spatulae are so small that they are sandwiched between the toes and with the wall or ceilings, so that the lizards are in direct contact with their environment.

Scientists are also able to isolate a single spatulae. The study of it reveals that the spatulae are working like adhesive tapes or like Velcro. Scientists are interested to find glue or adhesive tapes similar to the spatulae of the toes of the Lizards.  The new product will be useful to construction workers, mountain climbers etc.

All living things in our ecosystem have great significance. We have to co-exist with other members of the ecosystem to understand and to use it for our wellbeing.We have to study their anatomy, physiology and morphology and understand their lifestyle. We have to learn their behaviour in their environment and develop techniques to better our lifestyle to help us to become the masters of this universe.