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
Merriam's kangaroo rat rats produce up to three litters per year, with an average of four pups in each litter. Weaning of young occurs 24–33 days after birth. The diet of Merriam's kangaroo rat is almost exclusively plant seeds (they are granivorous). The bulk of their diet consists of the seeds of desert and grassland plants. They rarely drink water. Rather, they obtain water through metabolic processes augmented by the moisture content of their food. Kangaroo rats are a common prey items for many other desert animals. Typical predators of the Merriam's kangaroo rat include barn owls, great horned owls, coyotes, foxes, badgers,