While blood collected from mosquitoes won’t be used to clone dinosaurs any time soon, it may one day be used as a tool to solve crime. A 2015 study published in the journal Genetics and Molecular Research [PDF] shows that human blood taken from the digestive tracts of mosquitoes in closed environments can provide accurate DNA profiles of the people nearby—perhaps including suspects.
To test their theory, researchers collected blood consumed by 26 female mosquitoes from two homes. From these samples they were able to assemble 11 DNA profiles that matched up with the saliva samples they had taken from the homes' residents. Mosquitoes have a tendency to feed quickly and remain at the site, so it's theoretically possible for specimens found at the scene of a crime to have bitten the perpetrator and stuck around for hours to follow. And because different species are active during different times of the day, a mosquito with a belly full of incriminating DNA that’s known to be active around the same time the crime occurred could add an extra layer of evidence to the case.
Another advantageous quality is that the mosquitoes only stop feeding when they're full, even if it means drinking from multiple hosts. Mosquitoes containing more than one DNA profile could possibly provide links between victims and criminals in future crime investigations.
The support for mosquitoes' crime-solving potential was so strong that the scientists behind the study urged investigators to begin collecting the insects at indoor crime scenes. If unknown human blood was found inside one, they could run it through a DNA database of criminals. So next time you get annoyed by mosquitoes in your home, just think of them as tiny forensic detectives.