The mosquito trap killer in the bedroom must be opened in advance(at least 3 hours). Do not turn it on until bedtime. Do not open the bottom tray immediately in the morning because the mosquitoes trapped inside the tray may fly out. Keep it running for 2 more hours so that the mosquitoes suffocate to death. For the trap to work efficiently it should be placed far away from the fan and the room should be kept as dark as possible. The effect is better in uninhabited environment, because people’s body temperature and smell are more attractive to mosquitoes. This product uses the physical way to kill mosquitoes, it can’t kill a mosquito when just turning it on.