It kills flying insects and bugs but you should use bait for best results. It also clogs. It could also catch fire if you don`t clean it. Keep it 3 ft.away from the house. The smell could reach 5 ft. Spiders will spin webs on it then fry themselves. It killed a large praying mantis. Mount it in the air. A replacement bulb runs $10 or more so keep that in mind. I had the earlier version of the BK-80D programmable and it fried the bulbs too fast. Replacement bulbs were $28. However it did seem to kill more bugs. The newer BK-80D seems to be an improvement and worth the purchase. The bulb is only about $15. Shop Wal-Mart first.