Predators such as raccoons, birds and cats can pose a risk to your fish and plants. So predator protection such as pond nets and motion-sensor sprinklers are necessary. Pond nets are the most animal-friendly manner to protect your pond. Pond nets are laid across a pond's surface so animals can't get to the vegetation or fish within. Predator netting also is also a safety precaution for pets and small children. Predator netting costs $14 to $115 online. Wooden fencing costs approximately $100 online, and can be used alone or in combination with netting. Another form of animal-friendly predator protection is a motion-sensor sprinkler. These sense predators and spray them as they approach your pond. The most extreme predator protection is an electric fence that surrounds the perimeter of the pond and shocks intruders. However, electric fences won't protect your fish from flying birds.