Heres a homemade prevenitive maintenance recipe for pest.
2 tsp. Dr. Bronners Peppermint Soap/gal
4 mL Sesame Oil (Or Canola oil)/gal
2 mL Rosemary Oil/gal
Emulsify with a silica product (usually 5 mL per gal)
Shake well.
Spray once a day, every day for a week.
Spray once a week for prevention if you don't have any pests.