Sanjana Kapur from Bengaluru asks, “Will mosquitoes ever become extinct? How will that affect us?”

Mosquitoes have been around for over 100 million years and there are more than 3500 species on the planet at present. It would be safe to say that they are in no danger of becoming extinct, except that they’ve made one powerful enemy – humans. While only some mosquito species bite humans, and only some of these spread illness, millions of us are affected every year by mosquito-borne diseases like malaria, dengue fever, chikungunya and yellow fever.

G Brahman asks, “Why does a mixture of cornflour and water act as a liquid as well as a hard surface? Our teacher said that it is because of surface tension, but how?”

I hate to break it to you, but your teacher seems to have gotten it wrong. Surface tension refers to the tendency of liquids to form a kind of ‘skin’ on their surface.

Ranjani S from Chennai asks, “Why do some colours in photographs appear different from the original colours?”

First, some quick background. Our eyes have many little light receptors called cones. A cone may be sensitive to either red, blue or green light. (Not those colours exactly, but close enough.) Our brain combines the responses from these three types of cones to form all the colours that we see.

“Why does passing an electric current through wire coiled on a conductor make it act like a magnet? I asked my teacher, but she said it was because it was a law. I am not too pleased with this answer and thus put forward the question to you,” says Ishita Gupta.

Ranjani S asks, “How is rainwater pure when the evaporated water from lakes, rivers and oceans is salty and impure?”

If you’re sipping on a glass of fresh rainwater as you read this, you might want to put it aside.

Revanth Kausikan asks, “What is the blood group of a mosquito, given that it sucks blood from everyone?”

As someone who is constantly swatting and slapping at mosquitoes while others remain untroubled, I have a related question myself: why me?! But first, the mosquitoes.

by Dr Srinath Perur

Tanvi Nayaken says, “I am curious about life on other planets. Do aliens really exist and are they among us?”

Our universe is so vast, and it contains so many galaxies, stars, solar systems and planets, that it seems possible that life exists somewhere out there. But first, let’s get to the bottom of what we mean by ‘life’.

by Dr Srinath Perur

Is it true that some insects are only seen once every few years? What do they do in between?

Yes. Several insects like the pine bark bug and some moths have what is known as a periodic life cycle – they are only seen every two or three years. But the most interesting of such rarely spotted insects is the periodical cicada, found mostly in North America.

by Dr Srinath Perur

Different people can count a different number of stars in the sky, based on how and where they count from. If you count during the day, you will see only one star — the Sun.

by Dr Srinath Perur

Anoushka Kulkarni from Sangli, Maharashtra, asks: “Why does the taste of a mango change when it ripens?”

The taste of a mango changes when it ripens so that we feel like eating it. This sounds silly, but it’s true! Trees cannot move, but they want to spread far and wide like all other living things. So they make their fruits delicious to animals, which then eat the fruits and drop the seeds in distant places.