Some species of damselfly have elaborate courtship behaviours. Many species are sexually dimorphic, the males often being more brightly coloured than the females. Like dragonflies, they reproduce using indirect insemination and delayed fertilisation. A mating pair form a shape known as a "heart" or "wheel", the male clasping the female at the back of the head, the female curling her abdomen down to pick up sperm from secondary genitalia at the base of the male's abdomen. Sperm transfer is indirect. First, the male moves sperm from his primary genital opening (on abdominal segment 9) to his secondary genitalia beneath abdominal segments 2-3. The pair often remain together with the male still clasping the female while she lays eggs within the tissue of plants in or near water using a robust ovipositor.