Scientists reveal why mosquitoes prefer human blood over other animals

Have you ever wondered why mosquitoes are mainly attracted to human blood over other animals?

The scientists from Princeton University in the US believe that it has a lot to do with our ‘citrusy’ scent.

According to the study published in the journal Nature, mosquitoes evolved to bite humans by solely relying on odour molecules which are distinct from those emitted by other creatures in a particular environment.

These Aedes aegypti mosquitoes, which act as carriers for diseases like Zika, dengue and yellow fever, strongly prefer human odour over animals, The Independent reported citing the study.

The scientists arrived at this conclusion by scanning mosquito brains at a very high resolution to see how they would react to different types of scent.

To achieve this, they genetically engineered the mosquitoes to make their brains light up when they were active, and expose them to different types of scent.

To test how these blood-sucking flying insects differentiated between mammal and human scent, scientists collected hair, fur and wool samples and used odour from 16 humans, two rats, two guinea pigs, two quails, one sheep and four dogs.

They then collected human and animal odours non-destructively and designed a system which allowed them to pass human odour at the mosquitoes in the imaging setup, the UK-based newspaper reported.

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The scientists then found out that mosquitoes have been using just two of their 60 glomeruli (nerve centres) to detect the human odour.

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The mosquitoes use these brain centres to detect two chemicals – decanal and undecanal – which have a slightly orangey, citrusy smell and are enriched in human odour, the study concluded.

(With inputs from agencies)