Working principle: The mosquito and fly killer attracts mosquitoes by triggering photocatalyst (photocatalyst reaction) to simulate human breathing. Dehydrates and Dies Mosquitoes Safely and Effectively: No Chemicals, No Pesticides and No Odor, Kills all flies and bugs without the use of insecticides or dangerous chemicals. The fly trap features an ABS plastic housing and a durable LED bulb for quality and safety that will last for years! Suitable for home, office, kitchen, restaurant, school, hospital, etc. EASY TO CLEAN: The mosquito zapper and fly trap are easy to clean; dead flies are trapped in a neat, hidden tray located on the bottom of the unit. To clean, simply remove the tray and wash with warm water.