It´s not the pressure of sound that physically will push the pest away
It´s the randomly emitted unstructured hideous sound waves that stress the pest to give up the premises. Pets that already experience chaotic waves of various "human" ultrasonic sounds from tube lights, TV-sets, radio, refrigerator, etc. normally feel quite safe living close to their master and won´t be affected by the electronic pest management device, maybe apart from rodent pets that might find the noise irritating. Since electronic pest management at best should be installed in the attic and/or in the crawling space underneath the house it will not be a problem for rodent pets either.