What do you do when the very thing you deploy for protection attracts the offender? New research presents this dilemma for the users of DEET, an active chemical present in some of the biggest brands of anti-mosquito liquids and ointments. A study led by Claudio Lazzari of the University of Tours in France suggests that the presence of the chemical tells preying insects where to zone in. The worry is that these products are often recommended as the last lines of defence against deadly diseases like dengue and malaria. It comes not long after the revelation that smoke from mosquito coils could be as harmful as that from tobacco. Drives to remove the conditions that allow breeding of mosquitoes need to be upped again as the monsoon advances up the peninsula.