Why don't the invisible fences work?

Invisible fences may not work effectively for several reasons. First, some dogs may have a high pain threshold and choose to ignore the correction or become desensitized to it over time. Secondly, environmental distractions, such as other animals or people, can motivate a dog to cross the boundary despite the warning. Additionally, improper training or inconsistent reinforcement may lead to confusion and failure to respect the invisible barrier.