Insects sometimes land in your food, and sometimes they may bite you. If that annoys you enough to want to kill them, think twice.

Insect numbers are falling very quickly across the world, and that is a great danger. Insects play a very important role in food production and in protecting the living world.

"If we kill all the insects on Earth, we will die too," said Dr Erica McAlister, senior curator at the Natural History Museum in London.

When animals or plants die, insects descend on them, speeding up decomposition, which in turn increases soil fertility.

"Just imagine what the world would be like if insects did not clear away the droppings of people, animals and birds. Without insects, we would have to live among excrement and dead animals," says Dr McAlister.

Birds, bats and small mammals, meanwhile, survive by eating insects. Sixty per cent of vertebrates depend on insects to survive.

"So without insects, birds, bats, frogs and freshwater fish would also disappear," says Dr Francisco Sanchez-Bayo of the University of Sydney.

Insects are sometimes food for others, and sometimes servants of the ecosystem.

Source: BBC Bangla. First published in Bengali on The Agro News.