The high frequency sound waves produced by the dust mite controller are virtually silent and will not affect pets. Features: Just plug this compact dust mite controller unit into a wall outlet. It emits pulses of ultrasonic frequencies, which interfere with the growth cycle of the dust mite and inhibit its ability to sleep, eat or reproduce. Results are progressive, reducing dust mite population within 2 weeks. It can reach full effect within six months. For optimum performance, keeping it plugged in at all times also offers a bonus as a handy night-light.