diving beetles can be found in almost all freshwater habitats including rivers, ponds, lakes, ditches and even temporary puddles and with over 300 species are one of our most common freshwater inhabitants. Unlike the much larger great diving beetle (Dytiscus marginalis) these beetles are around 0.5 cm and arent much risk to fish or amphibians (large or predatory fish will try and eat them).
Though they are still  predators and eat small invertabrates they can also be fed bloodworm, daphnia and small insects, they will also scavange and will sometimes eat fish flake or pellet food. If being kept in an indoor aquarium, a secure lid is impotant as the beetle is able to climb.