A sure way to keep mosquitoes and other pests from ruining your backyard summer parties is to install a automated misting system. Placed in strategic but hidden locations throughout your yard, such a system will periodically spray chemicals into the area, killing the unwanted pests. 

Most mosquito misters use pyrethrum, an insect killing chemical derived from chrysanthemum flowers. Pyrethrum is harmless to humans and animals in small quantities, according to the Environmental Protection Agency, but can be fatal to fish and beneficial insects like honeybees since it is fatal to all insects. 

The EPA does not regulate misting systems, but does regulate pesticides including pyrethrum. For home use, it recommends the following: 

• Read all chemical labels carefully and adhere to guidelines regarding use and strength.
• Set the timing device on your misting system to times when pets and children are less active, say, at night or in the early morning. This is also a time when mosquitoes are likely to be active.
• Make sure mister is less than 10 feet high to reduce the chance of chemicals drifting into neighbors’ yards.
• Make sure nozzles are directed at targeted area and away from eating areas, pools, fish ponds and air conditioner vents.
• Make sure the system is child and pet proofed so there are no accidents.
• Turn off and disconnect the system when not in use for extended periods of time.
• In case of a leak, turn off your misting system and call your mosquito installation company immediately for an inspection. 

Following these general rules, according to the EPA, will help ensure your backyard is not only pest free, but safe for people, pets and the environment.