What kind of devises work as mosquito repellents and what is good mosquito control? Some things that don't work at all would be things like "bug zappers" that electrocute bugs. Most times these machines wind up killing more beneficial insects other than mosquitoes and they will attract more mosquitoes to your yard. Citronella candles don't really work that well especially out in the open like on a deck or in the yard. You need several to have even a slight affect. They work better in semi enclosed areas like a sun room or screened in porch. Now for some effective control. There are machines out there now that emit carbon dioxide which attracts mosquitoes and then sucks them in with a vacuum. Some of the brand names are Mega Catch or Mosquito Magnet. These are pricey but effective. Another method is the old fashioned fogging that professionals do. They also sell mosquito dunks to applied to areas of large free standing water like big puddles where mosquitoes will breed. These products prevent reproduction. These are some of the methods to consider this summer as you prepare for that outdoor barbecue or picnic.