Pest control without synthetic chemicals
12-15 drops of Peppermint oil, 8-10 drops of Eucalyptus oil dropped into 0.5 oz dish soap diluted in 12 oz water spray bottle.
Fragrant and strong! The soap + oils will help the scents remain in humidity and weather.
Repels (low concentration of essential oils) or kills (in higher concentrations): Fleas, Ticks, Wasps, Spiders, Mites, Chewing Lice, Earwigs, Millipedes, Dust mites!
Essential Oils can be obtained in quantity online, pretty easily: