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 front paws. The female Heermann's kangaroo rats also fondle her babies after birth with fondling, smelling, and licking. The young are born bright pink, wrinkled, hairless (except for colorless vibrissae), poikilothermic, and with their eyes closed. Within 22 hours of birth, hair is already developing and beginning to obtain adult pigmentation, beginning at the head and eventually reaching the feet by day 7. Before day 9 it is not possible to differentiate sexes because external genitalia appear the same. Weaning is completed around day 25, and young begin hunting and scavenging independently by 4 weeks. Heermann's kangaroo rat Heermann's kangaroo