Copper Nikus writes "An article at the BBC makes a shocking claim about mosquitoes. It appears some individual insects in the wild have developed the ability to ignore the very popular DEET repellent after a first exposure. From the article: 'To investigate why this might be happening, the researchers attached electrodes to the insects' antenna. Dr Logan explained: "We were able to record the response of the receptors on the antenna to Deet, and what we found was the mosquitoes were no longer as sensitive to the chemical, so they weren't picking it up as well. "There is something about being exposed to the chemical that first time that changes their olfactory system - changes their sense of smell - and their ability to smell Deet, which makes it less effective."'"