Red kangaroo has the ability to freeze the development of an embryo until the previous joey is able to leave the pouch. This is known as diapause, and will occur in times of drought and in areas with poor food sources. The composition of the milk produced by the mother varies according to the needs of the joey. In addition, red kangaroo mothers may "have up to three generations of offspring simultaneously; a young-at-foot suckling from an elongated teat, a young in the pouch attached to a second teat and a blastula in arrested development in the uterus". The kangaroo has also
Heermann's kangaroo rat range from , and their tail aids in providing counterbalance. Heermann's kangaroo rat has a wide window in which it primarily breeds, ranging from February to October. Its highest breeding activity is in April, and this decreases in July. Heermann's kangaroo rat rarely show increased levels of sexual behavior. Copulation is rather quick, and typically only lasts a couple seconds. If the animals are caged, the rats show no increase in sexual behavior. Females rats will even show aggression if her genitalia are swollen and enlarged. During labor, the female rat will assist the delivery of the young with her