Our Super Indoor EnviroBug Mosquito Killer Traps work by attracting mozzies to the trap using a blue light, emitted at a wavelength that is irresistible to mosquitoes. This light attracts them to fly in through the top of the trap. A strong internal fan sucks them down into the basket attached to the bottom of the trap where the constant flow of circulating air kills them by dehydration. NO Smells! NO stinky fluids to deal with!