Velda Heron Deterrents
Their Heron Pond Guard detects the movement of predators in your garden, quickly deploying and flash of light, and a sound to scare away predators. A little more aggressive, it is still not harmful for the birds and cats, just enough to give them cause for concern, making them think twice about a raid.
Their Heron Stop fences are a more secure way to protect your pond. A wire fence like the Heron Stop (and its mildly electrified big brother) create a physical barrier against herons, and correctly deployed, against most cats too, preventing them from gaining access to your pond.