Viviparity

thumb|An aphid giving viviparous birth, an unusual mode of reproduction among insects In animals, viviparity is the development of the embryo inside the body of the mother, with the maternal circulation providing for the metabolic needs of the embryo's development, until the mother gives birth to a fully or partially developed juvenile that is at least metabolically independent. This is opposed to oviparity, where the embryos develop independently outside the mother in eggs until they are developed enough to break out as hatchlings; and ovoviviparity, where the embryos are developed in eggs th

thumb|350px|The characteristic quivering abdomen caused by movement of tadpoles within a pregnant female [[Limnonectes larvaepartus]]