Aiming an Ultrasonic Device at a Neighbor's Dog
No law names the device, but pointing one at an animal you do not own creates cruelty, nuisance and trespass exposure. And you cannot see what it does.
Pet Safety
Pet Tech for Apartments: A Real Buying Framework
Before buying any pet gadget for a small apartment, run it through four questions about power, space, noise, and what happens if it fails.
Do Ultrasonic Bark Devices Work in an Apartment?
Ultrasonic bark control devices are marketed hard at apartment owners. Here is what the evidence actually shows, including where vets disagree.