The mosquito traps works by emitting a stream of carbon dioxide to mimic our breathing, once they notice that they are sucked up into the net and die. No open flame is used with the propane tank so it is safe to use outdoors. The company says you can either put the Mosquito Magnet by the pests breeding grounds or by where you are going to be. I have set mine up in the back yard, where the pond is, but near to the place my children enjoy playing and have noticed a huge reduction in the amount of mosquitoes that we have to deal with. The Mosquito Magnet Defender covers about half a acre and they do have other models that cover up to one full acre but for my families use this one is just perfect. I do not know how i would have made it through the summer months without the Mosquito Magnet, finally my kids can go outside and play without such a high risk of being bitten by these annoying insects that also do carry disease. The money we spent on the Mosquito Magnet Defender was defiantly worth the peace of mind we now have knowing that the risk of becoming sick or just laying awake all night scratching is a thing of the past.