Most hemipterans feed on plants, using their sucking and piercing mouthparts to extract plant sap. Some are bloodsucking, or hematophagous, while others are predators that feed on other insects or small invertebrates. They live in a wide variety of habitats, generally terrestrial, though some are adapted to life in or on the surface of fresh water (e.g. pondskaters, water boatmen, giant water bugs). Hemipterans are hemimetabolous, with young nymphs that somewhat resemble adults.