Why do mosquitoes bite some people more often?

Studies have shown that some people attract mosquitoes more than others. What is the reason?

According to scientific research, mosquitoes prefer blood group I over blood groups II, III and IV. They identify a person’s blood group by smell.

Approximately 85 per cent of people release chemical substances that indicate their blood group. Therefore, mosquitoes bite them first.

The blood group of 15 per cent of people does not produce an odour.