Remove dead vegetation around the pond to reduce the population of overwintering adults. Adults are a quarter to half an inch long. Adults grow up to 1.5 inches depending on species while some larvae can grow to 3 inches. There are at least 500 species in North America alone. The larvae are called water tigers and have sharp pincers to eat tadpoles, their siblings, and other critters.
Adults eat bugs, fish, tadpoles, each other, and frogs.
They bring air bubbles underwater with them to breathe. In some species, oxygen from the water can diffuse into the bubble and extend the time a beetle can stay underwater. Adults spend a lot of time flying around and show up at night lights. During the winter, they stay in the pond. In China, some people eat them.