Pesticide spray by homes

The farmer at this location sprays pesticide at nighttime, usually after 11pm. We fell asleep with windows open and woke up to house that smelled like poison. Spray gets everywhere, including backyard patio furniture and swing sets for kids. Is it legal to spray pesticide at nighttime when its pitch black? How would they be able to see if the spray is entering people's yards? Look at how close this farm is, its surrounded by houses.